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.

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.