Good score! i guess criteria this time was high because last year they called me at 64 score this time they did not :P

well the interview will last ~30mins, they will ask you a little about your fyp. Then they will ask you for your transcript.
In the transcript they will look at what courses you have studied and will start asking questions from those courses.

You should prepare very well from analog electronics and digital electronics(DLD also).
e.g they will give you a paper and pencil and will ask you to make a particular OP-AMP, or give you a circuit and will ask you to calculate output voltage or output waveform.
I don't know if they will ask from telecom courses or not but prepare the above two in detail.
It is a technical interview