Applied via the online portal in the CS dept website. Was contacted by the professor and asked to submit a statement of purpose as to why I was interested. Then the professor asked for official documents like transcript and bonafide certificate. After a couple of weeks I got the acceptance email of the Internship.

2 rounds of interview purely focused on technical aspects, last round would be done by professors. expect a m.tech degree with passion in research and a good gate score. Round 1 is easy but round 2 is hard.