Sir I am a BTECH final year CSE from NIT silchar. I want to do my Post Graduation from NUS, what should i choose MS or Phd.

Hi Panchratna, Since you have done BTech from NIT Silchar, you are eligible for MS course only. Phd requires a masters level degree as eligibility criteria. So once you are done with MS, you can go for Phd. Most of the US universties provide this as an integrated course(MS+Phd).