First round- Written test of 2 hrs(includes C,Microprocessor,java and aptitude)
second round and third round- Technical interview(C,JAVA,Microprocessor) Its a minimum 45 mins interview. They will ask most the concept of programming so be confident and answer as much as you can. They may also ask you to write codes and explain them. So prepare well.
fourth round- HR interview(just a formaility)