Other people in my small startup are getting 4 lakhs more than me with all of us doing the same work with same efficiency but because they are from tier1 college and I am from tier 2 college .How should I negotiate with the manager?

If you didn't know their salary would you be underpaid?

Simple, a management that pays based on college's tier will very likely not try to match your pay with them no matter how smart you're compared to the tier-1 folks. You stand a chance if you're in tech. Otherwise you're most likely to be disappointed again.

Resign, of they offer hike take it. That's the only option you have.

It is what it is.