Hello Jitendra, 

As per your question, most of the NITs demand for a minimum of 60% or 6.5 GPA in graduation for general/ OBC category, if you want to enroll for masters degree in NIT. So, as per the admission guidelines most of the NITs won't allow in their counseling if you have less than 60% in your graduation. But, I think you can try for entrance exam conducted by good ranked Central Universities as in some of the universities the minimum marks required is 55%.

Refer to the link below for details about M.Sc admission into NITs, CFTIs-

https://university.careers360.com/articles/ccmn

I hope this answer helps you. All the best.