Because of having 75% through my academic career, TCS conducted direct interview so i didn't attended for Written exam.
But from my friends i came to know that most of the questions are from Permutations , Probabilities.Most of the questions are previous questions only.

Interviewer is very cool person asked me about the subjects in PG then started asking each subject overview and asked me to give the real-time interpretation.It went on like a casual discussion.Later he moved to C(basic Programming) and Java(since i mentioned in my CV).
HR- it is only 2 minutes personal background, interests and futher plans.

All the Best :)

Interview is very simple if once written is completed every one can get throw.