Your best option in India is usually to leave and apply in Europe or the U.S. because the Indian market is very small and tough to break into without attending one of the top ~2 IIMs and getting in right out of that. If you’ve already graduated, I’m not sure your chances are great, though you do have some very good experience.

If you don’t want to move abroad, another option might be to think about boutique investment banks in India. This interview is from a few years ago now, but there’s a pretty good account of a startup-focused bank here:

https://mergersandinquisitions.com/startup-investment-banks-india/

In general, IB is not a good background for most startups / entrepreneurial ventures because you don’t gain any sales skills at the junior levels, and starting a company is mostly about sales. There are some exceptions where domain expertise can help, e.g., with a fintech startup or something geared toward financial services companies as customers, but working as an Analyst or Associate in IB has almost nothing to do with, say, starting an e-commerce company.

Most people who start successful companies after working in IB could have done it without the IB experience and usually just picked banking because it was a “safe” option at the time.