First things first - Have you had any experience prior to opting for M.Tech? The ground realities about challenging work environment and excellent global projects is that every big IT company out there has quite a few of them. Also, growth in big Indian IT companies is more or less the same and depends highly on your performance.

The best thing to do is contact the recruiters or the HRs of the companies that are in touch with you and discuss the projects with them before you make your choice. Ask them if they could introduce you to the project managers to have a conversation with them about the nature of job, profile etc. I'd recommend not having 'salary' as a criteria if it's not one of the top priorities. You can always opt for a better salary by making a switch to a new company. If I were you, I'd take my decision on the basis of the project the company is offering to me and the best answer can only come from the officials.

thank you very much BIG_K...

I am a fresher.... i don have any previous experience..... Since i have got placed in campus placement ... i don have any feasible way to contact the project managers of those companies.....

which of these will offer me a good career growth is the confusion

I am a fresher and I am a B.Tech graduate in the final year