Hello Arka,

Usually candidates with a GPA above 8 will have a good chance to get into reputed institutes like IITs ,NITs, IISC etc. Since your friend has finished M.Tech degree , GATE will mostly be optional and more emphasis will be given for the thesis work, the call for interview will be based on the quality of research proposal. However, some institutes may have a written test and interview as a part of their selection process. So visit the official website of the institute you wish to join for more details on the selection process. Regarding the stipend ,usually minimum it can be around 28000-30000 per month which may increase after 2 years as you become a senior research fellow . The duration can vary from 3-5 years but it can also be extended based on the research requirements.

Hope this helps