Consisted of questions based on Quants,verbal ability,Logical reasoning and core electronics.
The aptitude section was on moderate level of difficulty whereas the electronics part was more on an easier side.
The technical i.e the electronics part had questions from digital logic design and analog circuit design .These could be easily solved if one is thorough in concepts mentioned in above areas.

This was not an elimination round.GD had 10 participants and the topic was general.The score was to be added in the final interview score for selection process.

There was no separate HR round . The panel had 2 persons, one technical and one HR.
The technical person asked me first to give a brief introduction.He then questioned about the extra courses I have completed.After this he asked which is my favorite subject,upon which I told him analog design and DSP.
Thereafter the interview went completely on operational amplifier design and applications.
At the end he asked whether location is a constraint.At the same time HR asked his first question throughout the process and it was an easy one.
At no time they looked at my resume . Instead they were using a form which had to filled before the interview.

For aptitude good references are internet and previous year CAT questions.
For technical section be clear with digital and analog electronics concepts and applications.
For GD the key is to balance the quantity and quality of your speech.
For interview ,confidence in speech is necessary .Moreover a good proficiency in your favorite subject of the curriculum will definitely help a lot in cracking the interview.