After completing M.Sc. from IIT one can give Gate only if he or she want to pursue a career in Public Sector Units like Indian Oil, NTPC, BHEL, SAIL or perhaps public research organizations like CSIR Laboratories, BARC, BIS or DRDO.

Many even aspire to pursue a Doctoral degree after Masters from one of the Top IITs or IISc Bangalore, hence GATE is mandatory for that. Even if he/she wishes to pursue Ph.D from the same IIT where masters degree was completed, he/she has to give GATE in order to be eligible for the Ph.D monthly stipend.

GATE Scores are also accepted by Many Foreign Universities like NUS and NTU in Singapore as well as TUM Munich and RWTH Aachen. So if a student wants to pursue doctoral degree or research from the above world renowned Universities, again GATE Score can be a means of entrance besides the usual GRE route. Hope that helps.