Chose a Startup over TCS. YOU'LL LEARN NOTHING IN TCS TRUST ME.
About tech stack no other environment will help you learn more technologies than startup ecosystem.
Processes in Service based IT firms is nothing but show off. They don't follow it with integrity. And it's less of an important trust me. Everything is crisis management at the end.
Don't be scared, choose the startup thing. And also demand a bonus of 1.3 Lakh for the Bond. You make it a point that you are committing to the company it financially can help you too. The contract to be renewed based on what they offer. Else you can also negotiate about if you leave after 12 months 18 months and 24 months how much money is they plan?
Because it's also your first career and you are serious about it. If something doesn't serve your skills and interest money shouldn't be the reason to stay there it's like choking yourself.
Another thing, you can abscond if you don't like the job. Nobody is gonna sue you. I have don't that as fresher with a company and nothing happens they have better things to look at than running after 1.3 L with an employee.
Thank me later. :) Good Luck