As both the colleges are good but if you talk about rating and ranking then as per Careers360 VIT (main campus) has got AAAA+ which shows this is an outstanding college to pursue Engineering courses and VJTI has got AAAA which says this is also a very good option but not better than VIT (main campus). But it would also be better if you could consider your interest and potential before you make any decision. To know about both the colleges in a better way you can go through the below provided placement records -

VJTI Placement

VIT Chennai Placement Stats

Hope this helps!!!

According, to Careers 360 VIT Vellore has AAAA+ rating which means outstanding and VJTI Mumbai has AAAA ratings which means very good. Both the colleges are good. If we compare both the colleges in terms of placements, exposure, faculty and Infrastructure then VIT Vellore is better college.

You can also check the placement record of both the college from the given below link

VIT Vellore Placement Record

VJTI Placement Record

Good Luck!!