How DRDO interview different from other PSU's

Interviews are the last stage in the selection process for any job in Public Sector PSU like IOCL, ONGC, BPCL, GAIL, SAIL, NFL, NMDC, NPCIL, HPCL, NTPC, BHEL or in government sector such as ISRO, BARC, DRDO etc Interviews are also very important for selection in M Tech, MS and PhD courses in Indian universities such as IIT, IISc, IIM, NITIE as well as foreign universities. Interviews in IIT IIM etc for MS PhD FPM are done in summer as well as for winter admissions. Winter admission in IITs for MS PhD courses has very high probability of selection and is normally at low GATE score.