SIR ,I AM DOING MY MECHANICAL ENGINEERING DEGREE AND CURRENTLY I AM IN MY LAST YEAR AND I AM PLACED. I HAVE GOOD RANK IN GATE 2011 ME SO I GET IIT FOR M.TECH. SO WHETHER I DO JOB OR DO M.TECH FROM IIT FOR GOOD JOB

It is totally your choice.It all depends on your interest.If you want to go in the hardcore research area like R&D and Validation, you should take M.Tech., that too from IIT will give a very good brand status.

Unlikely to this, if your job offer is good, may be you may go for it.If you can furnish me other details like the company in which you are placed and your role, I will be able to better suggest you.