Hello Madan,

Both the colleges have its own pros and cons.

The ratio of number of companies visiting campus to nunber of students is more in IIIT Allahabad. In simpler words more opportunity in IIIT Allahabad. 

As per ranking IIIT Allahabad is at better position than NIT Durgapur. Even fests are better than that of NIT Durgapur. 

But at NIT Durgapur you'll enjoy all the name and fame of college. Fees is also less and you'll get good job opportunity. 

But I'll strongly suggest to go for MNNIT.

All the best!