With a rank of 81844 in VIT, it is a bit difficult to get BSc Computer Science at the Vellore campus, as it usually has higher demand. However, you may still have a chance in the Chennai campus, as the cut-offs there are usually a bit lower compared to Vellore.

Still, it depends on the number of applicants and seat availability this year. You should attend counselling and keep both campuses as options.

Hope it helps !