With an M. Tech. Degree, you can apply directly to any department. The departments have their own processes. Ours takes written (gate level questions) and interview (basics). I was asked simple concepts, definitions, and then was asked to solve a few small numericals on board. They are mostly focused on your approach.

Good and informative when it comes to questions. Basic knowledge is required to crack the interview. Start with basic gate questions and have genuine research ideas to excel. Professors will make you feel comfortable but they will prey on you the moment you go or deviate from basics. So be careful

a written test was followed by an interview. They focus on fundamental questions and assess your problem-solving abilities and enthusiasm by interacting with you gradually. They start with simple questions and if continue to answer them they will dig deeper and will look through your thinking ability.