First round was an aptitude test. 40 questions in 45 minutes (quant, verbal and DI). Easy enough. Work on the easy questions which you can solve in 60 seconds or under and leave the the time consuming ones. Some 50 out of the 150+ candidates shortlisted for the next round (the interview process) after a 30 minutes ppt. They conducted 2-4 interview rounds depending on the candidate and each round was elimination. Most of the candidates were selected after 3 rounds, few after 2 or 4.
The questions were general HR questions, resume based and puzzles. Each candidate was asked around 4 puzzles minimum. The puzzles again were regular, nothing new. They recycled the puzzles between interviewees.
The first interview was mostly for screening out the non serious candidates.. some 20 were selected for round 2. The whole process took 2 days. one for the test and the next for ppt and the interviews(interview process -all the rounds- went on for about 6-8 hrs total).