Hi Alok,

In interview, first they will start with the basic introduction for 1 minute and next they might ask "why do you want to do M.Tech?". Next, they will expect basics of electronics and questions based on them especially sequential circuits. In semiconductor devices be very thorough with the concepts of Fermi level and carrier concentration. Later, they might ask you from the topics : scedra and smith, biasing a transistor,  small signal models, opamp based circuits and feedback. These are the main topics they might ask questions from. Last, they will do some interaction with you like about your hometown or your hobbies etc.

Hope it helps, thankyou!