I am a Big Data Engineer in India with 5 years experience. I have been offered a job in a start up in Berlin with 51k euros fixed salary and 5k euros variable annually.

I have a family of 4. My wife, 1 son(who goes to school in class 2) and 1 daughter(6 months old).
Is the salary sufficient to survive and possibly save a little?

Yes.

You will probably have a relatively small flat relatively far from the city center, but there are plenty of families getting by on much less.

• You will pay very approximately 5k € in taxes and 10k € in mandatory health insurance and pension etc. That leaves 35k € as payout, about 2,900 € per month. Add the children's allowance mentioned by kriscorbus in his or her answer and you will have about €3,300.



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  You might have to spend close to half of that on rent, heating, power. That's the big question mark. German law protects tenants with existing contracts against extreme price hikes, so any new contract will be considerably more expensive than average of the old contracts for the area. You won't be able to afford the most fashionable districts.

  
  
  
  • You should inform yourself about Berlin districts. Some of the cheapest ones are cheap because they're not nice. Some are more racist than others.
  
  
  • Where you live will also affect the quality of the public schools.
  
  



• The price for clothing, groceries, etc. depends on your expectations. Organic food is more expensive than regular, etc.



• Childcare could be a significant expense and finding a place could be a hassle. Does your wife plan to work?
  
  My personal advice is that she should look for a job as soon as she is able, perhaps 20 hours/week. It helps the children to go to German-language childcare and it helps her to get into German society.


• Many people have no car, they travel on public transport. The commute could be one hour or more, but a car does not always save much time and parking is a hassle. Either way, transport costs will be a factor.

51k Euros is enough to live, but not enough to save (OK, it depends on your habits and life expectations).

Germany has complex taxation system. I hope this HowToGermany page helps to get an overview. There are several benefits in taxation system for parents, like children's allowance. In your case 194 Euros per month per child, results in additional 4656 Euros in year. Next upgrade is already planned: it will be 204€/child/month.

Allowance is not depending on fact - is your wife working or not. But just like @o-m I would suggest your wife to look for child care (in East- Germany you can have day care already for 12 month old babies), start to work and start to integrate into society. In Germany child care is unique information exchange hub, do not miss it out!

Others have already told you that the answer is positive. I'd like to add a few points:

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  As an expat, life is usually more expensive because one lacks the cultural knowlege how/where to cut costs, e.g. which food is more or less expensive.

  
  
  
  • Eating out is expensive in Germany, cooking from basic ingredients is much cheaper, even if you go for better ingredients.
    
    This includes lunch at work: bring your own vs. canteen lunch customs vary between companies/groups/teams, but I've never met a place where bring your own was frowned upon. In many places you can even take your own to the canteen so you can join the lunch break talk with your coworkers (this and the coffee break are important for integration)
  
  
  • However, Indian ingredients are probably quite expensive, particularly fresh (exotic) fruit.
  
  
  • If you feel experimental, you may be able to arrive at variations of Indian food with more regional ingredients.
  
  
  • To get an idea of what is reasonable (or not) in terms of grocery expenses, there exist a number of recipe books ("Harz IV Kochbuch", student cooking books) that were specifically written with the purpose of being inexpensive and nutrious at the same time. In case that's important for you, there's also a vegetarian subset of these books.
  
  
  • There are also courses on cooking. E.g. at the so-called Volkshochschulen:
  
  



• Volkshochschulen offer affordable courses for adults and kids on a wide variety of topics, e.g. German language evening courses (also other languages) or cooking for kids as school holiday program.
  
  Such courses may also be good opportunities for your kids' integration.



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  Integration for a working professional isn't as easy as for international students. In Germany, sports clubs or "cultural clubs" (or maybe scouts group for the kids) are quite important. (Also, joining a sports club is usually much cheaper than a gym membership.) If you were in a volountary fire brigade in India, consider checking out the local one. This is the more important the more rural the place where you live.
  
  Resentments and xenophobia are often tightly bound to how hard-working (or rather: not hard working; as IT professional you're on the ) and how interested in the German culture you are perceived. Most important here: learning German.
  
  East Germany outside Berlin has few immigrants compared to the western Länder. But among them often the majoritymany * came there very suddenly in the 2015 refugee crisis. Having them in a region that keenly perceives that even after 3 decades they have not cought up economically with many western regions is a difficult mixture.
  
  I'm saying this because if you moving outside Berlin into Brandenburg the costs for housing drop very much: going out maybe half an hour by regional train could give you acces to much lower housing costs. How feasible this is will depend on a number of other considerations, of course.

  
  
  

  * update: I misread the IWH: United country – three decades after the Wall came down study: it allows to conclude that at the end of 2016, in many regions of eastern (and northern) Germany > 32 % of foreigners were seeking asylum, and @kriscorbus has kindly pointed out that mistake and commented that many of them have moved on (presumably into the big cities in the West and maybe into Berlin). I've been to Berlin + outside Berlin on and off in the last 2 years any my impression was still a comparatively high proportion of refugees - but that's of course just personal anecdata and may be totally different from one place to the other.

  
  



• In general, any kind of service is expensive (cmp. eating out) due to wages. Expect at least 50 - 60 €/h if you call, say, a plumber.
  
  When you rent a flat, there are certain types of repair that are up to the landlord. For everything else, if you are handy you can save a lot of money. Still, you may need to plan considerable time to get yourself familiar with products/working techniques that differ from how you do things in India (I haven't been to India, but I've found substantial differences between Central Europe and North America).




• International school with lessons in English is going to be expensive - but German language education from elementary school on is free (as in no tuition). Private schools do exist (with and without tuition), but ≈ 90 % of the kids attend governmental schools.

2900 Euro spendable income is 90% of the average family income in Berlin (source in German). And your family's earning potential is higher than your starting salary, as you could hope for a raise, or your wife could also start working, at least part time.

You won't be able to have a very lavish lifestyle, in the sense that many people you see will have something you cannot afford, for example a new car. But before you get jealous, you have to remember that those people have given up something else you are spending money on to get that car. It is only the rich ones who can have all signs of affluence at once.

With that kind of money, you won't be starting at the bottom of the social ladder. You may not be able to afford everything you see advertised, and you will probably live in a flat smaller and further away from the center than you wish (rent is currently really expensive in Germany), but many people you interact with on a daily basis will be living on less.

So this money will take care of "standard" daily/monthly/yearly expenses. Do not forget to protect against emergencies, these are especially hard if you don't have a network of family and friends close by. The mandatory health insurance (deducted before you get your 2900/month) will take care of all medical emergencies without any noticeable copayment. But you should get at least a Haftpflichtversicherung, which pays for damage you happen to inflict on other people's health or property (e.g. your washing machine breaks and floods the neighbour below you and you have to pay 20 000 for repairs). And, in your situation as a single breadwinner, seriously consider a good Berufsunfähigkeitsversicherung, it pays you a monthly income if you get disabled by disease or accident and can no longer work. You may hear that they are expensive, but the price varies by your occupation, and people who write software pay a comparatively low premium.