Which is better IIM or NICMAR?

It is pretty clear that IIMs are better than NICMAR. I am assuming you are talking about new generation IIMs. 

IIMs have a different reputation in the corporate world. All companies die to recruit candidates from IIMs, and in the future, run values of IIMs are only going to increase, and an IIM tag can help you in reaching a CXO level in the corporate world plus IIMs offer a great culture and students life, various clubs and committee and various case competitions in IIMs will help you grooming, and you can make some good connections with the IIM fraternity.