MTech in IIT/IISc CSE?

Graduated in 2022. Working in the telecom software domain.

I want to have the college experience again (COVID destroyed mine) and hoping get a salary jump as well.

How are the courses and peers in the CSE department in these institutes? Is it worth preparing for GATE and leaving my job to join these institutes? Or is it better to skill up and switch?

Current base:10LPA

Thanks,