If you are currently working somewhere then you should not think of doing M.Tech (if the placement is your point of concern) because at this score you will not get good college. 2 years of stipend and back at the same spot.
If those 3 years are of the gap then you should definitely think of going for something else as 3 years is a long time. Try searching for a job with a gate qualified tag, it might work.
Last take any college kickoff you M.Tech, prepare for easier exams like UGC NET-JRF and eventually becoming Assistant. Prof or Research Scholar. This is a slow, steady, and safe path at an expense of less earning.