See for central universities - there is the CUCET exam. However I dont see M.Tech in it being offered there. Have you applied for GATE? Because most of the central universities and states take the GATE Scores for admissions. In fact IITs, NITs and some IIITs take admissions on the basis of GATE scores. M.Tech admissions are also through some entrance tests in most good colleges - either GATE Or a state entrance exam. check the M.Tech admission details here -https://engineering.careers360.com/articles/mtech-admissions. If you have not applied for GATE, then you cannot apply now as the dates are over. However, you can apply for BITS HD, VITMEEE, SRMJEEE PG etc. IIIT Hyderabad offers it engineering through its PGEE exam. so pls check all these options and apply accordingly.