IIT JAM stands for Joint Admission Test for MSc, and it is a national-level entrance exam conducted by the Indian Institutes of Technology (IITs) for admission to MSc, Joint MSc-PhD, MSc-PhD dual degree, and other post-graduate programs offered at IITs, IISc, and other top institutions...
it helps a lot if you apply in the same topic for your PhD... In my case I am doing that in neutrino physics. Also, it being a year long project, this is what the applications committee (of your prospective grad school) usually focuses on... p.s. - whatever i am writing is ...