Must choose IIT ALLAHABAD .
I am fresher here but searched alot about this institute it provide best environment and best coding culture.
Whereas VIT Vellore is just hyped but it’s not good in comparison to IIIT ALLAHABAD also it’s in South so if you are from North it become difficult for you to adapt into the environment .
And here is extract from Wikipedia..
“In 2014 the IIIT Act was passed, under which IIITA and four other Institutes of Information Technology funded by the Ministry of Human Resource Development were classed as Institutes of National Importance.”