M.Tech from IIT is good for Computer science & Electrical people who want to get good jobs (above 10 lacs per annum). For all other branches like mechanical, civil, aerospace, energy science & interdisciplinary branches, there is a lot of struggle to get good jobs (most of them below 10 lacs), and its difficult to indulge in research because of hectic syllabus, lack of time, lack of world-class facilities as well as a lot of time goes in preparation of placements.
Except for computer science & electrical, Masters at IIT is not lucrative for other branches & one should try to get a PSU or government job based on GATE Score.
Edit: I observe some people are feeling that my answer is degrading branches other than computer science & electrical. However, these are solely my opinions and you are free to agree or disagree with it.