The most practical thing to do here would be to begin with taking a look at the syllabus of both these mentioned programs. You need to be absolutely clear about whether you wish to study for the next 4 years of your life and maybe also be able to develop a career in the same field. Interest and passion are mandatory to be able to sustain in any field of engineering for a very long period of time.
Now as far as my personal opinion goes, since two of my brothers have completed their engineering from IIIT Allahabad, I strongly believe that IIITA is a notch better than the others. Although the syllabus of CSE and IT is more or less the same, the overall academic environment of IIITA is better suited for coding when compared to the other NITs. There are a number of competitive programming websites available online where you will find more students of IIIT A placed at higher ranks than NITs.
There is a process of development, evolvement and growth as a programmer in IIITA for the students. It is known to all that India’s best coder Suryanarayana is also from IIIT A. Another reason why IIITA is a popular option for many aspiring coders is because unlike other colleges, it offers core subjects from the first years itself.
The placement scenario is also far accomplished of IIIT Allahabad.