What should I prefer, a PSU or an M.Tech? How is an M.Tech at IISC Bangalore? Also, which PSUs recruit for R&D sectors through the GATE?

It depends upon you whether you want to pursue your dream of getting a government job or pursue higher studies further. Either you pursue M.Tech from IITs or go for PSU jobs. It totally depends upon you what your interest level and what do you want to achieve as both are very different career options.

• M.Tech from IISC Bangalore will be a good option for you. This college offers better facilities, faculties, environment, and atmosphere.
• If you want to pursue research studies then this option will be good.
• If you want a job after M.Tech then you should go to IIT Bombay and IIT Kharagpur.
• If you want R&D Profile then you should select you should go for M.Tech from IIT.
• BARC, CSIR, HRDO and HAL recruit R&D profiles through GATE scores.

It finally depends on you and how you want your career to be shaped further. Because both have entirely different outcomes. Both can be equally good for your career if you are dedicated enough.