hey there!!

As per your rank and previous year cut off there is no chance of you getting mechanical branch in first category in vellore.

there is a slight chance that you might get mechanical branch in 4/5 category in vellore or you can go for chennai campus too. 

If you are willing to pay more then I would recommend you that you should go for the counselling as there is a slight chance of you getting mechanical branch in 4/5 category.

hope this helps

all the best!!