My interview consisted of three rounds. But this was not the case for everyone. Some had two and some even had one round. My first round was purely technical. Project related questions were asked but also questions were asked from subjects which I had not mentioned in my CV. So this was a difficult round for me. Luckily I was called for round two, which was a technical and HR round combined. This time I was asked questions from my CV and I had a better time. After that there was a third round for some students and I was one of them. And surprise surprise!! It was a GD round. Yes TCS does conduct GD rounds sometimes, so you should prepare for that also. My GD round was OK and I was selected after the process.