Easy of just about ½ an hour.. you would be given time to explain your topic and then the interviewer will ask u few basic questions about the subject you chose. And your results will be shared via mail

First a fall your Profile should Shortlist for The Position which you applied,The they call you inform you about your Shortlisted Profile.They will ask you about your availability to complete the further process to finish that job role,The Interview is Conducted in two stages.1)Telephonicc Call and 2)Interview with HR and 3) Interview with Main Manager