That's a multiple round process, first one aptitude round consists of 40 questions and you have to do that in 90 minutes and if you clear that again round 2 aptitude and reasoning that consists of 20 questions and you have to solve it in 25 minutes . If you clear both the rounds , then you are qualified for the next rounds. In the application process they mentioned that they'll give you 30 days time for preparing for math round and c++ round. But for me they gave me just 15 minutes. And the math round 1 was a bit tough and it is completely based on engineering mathematics and it should be completed in 90 minutes and there after math round 2 about Boolean algebra for 30 min. And the c++ round you will be having 5 programming questions with unlimited time. One who is attending the interview should be well aware of. Engineering mathematics.