Most of questions for ece background were on C,Data structures,OS and networks.It was referral drive.Aptitude was bit tough.M4maths.com would be helpful to prepare aptitude.First round aptitude out of 200 candidates 50 were shortlisted.followed by aptitude was technical round face to face out of 50 they selected around 15.I was not selected in this round.I think they selected 8-10 finally.