After B.Sc. and M.Sc. in Physics, you can pursue MTech in a respective branch of your Choice, provided you Crack GATE for that Respective Subject. Most of the candidates, who aspire M.Tech after M.Sc., do it in Interdisciplinary branches like Material Science, Intelligent Manufacturing, Robotics, Mechanical, Avionics, Engineering Physics, Industrial & Engineering Science, Computational & Data Sciences and many other domains. Incase you do the MTech from some of the IITs or Top Institutes like IISc Bangalore, you perhaps have excellent chances in securing good Placements.