There are various Exams out there for M.tech. I am listing few:

GATE, LPUMEE, VITMEE, SRMJEEE, TANCET, EAMCET, etc.

If the consider one  exam which covers all the IIT's, NIT's and most of the State Funded university then it is GATE.

65 questions are asked in the GATE. 30 questions of 1 mark and 35 of 2 marks. 25 to 30 questions are NAT type.

All the best!!!