Interview process is based on your technical knowledge and your personality. Also you have give an exam to get to that point. And from there, they can ask questions at the interview.

I applied via campus interview process at CIT, Coimbatore. The HR gave a detailed information about the company and nature of the Job. After the talk, a written test was conducted. The questions included basic electronics and mechanical knowledge. After that i was selected for face to face interview. Interview was comfortable. I got selected in the interview. Basic knowledge of your domain is important.