What is the difference between the different admission categories for VIT Vellore? I know there is a difference in the fees but is there any other difference?

No there are no major differences between the categories other than fees. But there might be some stuff that is different in terms of hostels once classes start on campus.

Feel free to pm in case you have some more doubts.

There is also a link in the comments to a group made for freshers to ask and have their doubts resolved.