Break up with him, now!!
If you are of the type who get offended, stop reading now, otherwise let me try to give some reasons explaining my stance.
If a husband asks a wife to sit back at home and take care of the kids, he is anti-feminist. All sorts of people will start attacking him.
Similarly, if a wife asks a husband to do boring work so that she can have a stable life, she is anti-masculinist.
Will you be accepting if he says, "I go to work, you sit back at home and take care of the kids?"
2. You complain that he does not understand the future.
Well, nobody does.
Once again, you are horribly wrong if you think you do. Here are a few things, you do not understand.
Having an IIT IIM degree means, you would never go to bed hungry, so most your risks are covered. There is always a job waiting for you.
Two, you earn. How much money do you need to live a stable life? A top-notch B-school graduate earns enough to feed multiple families (I would guess about 15-20 lakhs per annum), you are talking about just one.
Three, if he is creative, he would figure out ways to make money. I would have rather hated if my wife and my mother doubted my abilities.
If all your risks are covered, you are going to work anyways, what incentive is there for him to pursue a 'stable' life?
Most importantly, did you even try to understand why he does not want to earn?
Some people cannot do just any work thrown at them. They will either find their passion or die trying.
Assuming reasonable logical capabilities which are quite common among IITians, I am reasonably sure, he would give you one pin point reason why he does not want to do a job. (And mostly he will say, either he gets bored or he wants to make a difference.)
3. You assign blames.
According to his new plans we will be in different cities. It’s almost like long distance marriage that too for indefinite years.
What is your plan then? Can't you get a job in the city where he lives? Why is this specifically 'his' plan?
4. You are searching for reasons to break up.
The points where you mention your parents viewpoints and your friends view-points, clearly suggest, you are seriously contemplating the option. How would the marriage last if by chance, his first venture fails.
Your parents and your friends will come telling you, "I told you so." and you are getting to let it out on our poor guy. Solid signs of a weak marriage.
5. If you assume higher moral ground, then you do not love him.
Please do not do him any favors by loving him! If you want to want to marry him, marry him because you like him.
Do not assume higher moral ground if you are think you are marrying him despite his low income. It would be equivalent to him assuming higher moral ground if you were ugly.
What would happen if he follows your word and next day, he meets an accident. Will you dump him the next day? If yes, then you do not love him. If no, then why are you waiting for an accident?
6. Lose lose situation
At times I feel a guilt that our marriage won’t let him discover things because it will need a stable/settled life and some time he will have to give for family. One more thing when I ask about the future as he is unstable and doesn't know much about future, he gets upset for asking him that. I don’t want to see him sad.
See, this is a lose-lose situation even for you. If he follows what you say, you would keep on carrying this guilt and if someday he loses his temper, he is going to remind you about the sacrifices he has made. If he does not follow what you say, you think the marriage won't work and you are going to blame everything up on to him.
Please dump him, it will save two lives, yours and your partner's. Both of you will find people according to your life plans or the lack thereof.