First interviewer asked me about myself and then we had some discussion about project and then he asked me some oops questions and also asked me to write a code for some elevator problem

It was a campus placement process. Our of the 800 students , 93 were selected after online round. Next day, all of them were called for group discussion. Those selected further went for HR round and lastly had to face a rather long technical interview. The HR was very friendly and helpful. I was amongst the final 32 to get placed but still have not got the offer letter. I guess it's because of lack of projects in this company.