VIT Vellore

I don't think they have categorized the hostels based on seniority.
Refer to the URL below, you will get the complete idea about hostel blocks and rooms available there.
A-4AC, 4NAC, 2NAC and 6NAC
B-3AC and 3NAC
C-2NAC and 4NAC
D-1AC and 1NAC
D Annex-3AC, 3NAC, 4AC, 4NAC
E-2AC and 2NAC
F-2AC, 2NAC, 6AC, 6NAC
G-1AC, 1NAC, 4AC, 4NAC
H and J-1AC, 1NAC and 3NAC, 6NAC (new)
K-4AC, 4NAC, 6AC and 6NAC

First of all, make your mind whether you're going to pursue CSE or ECE because the most important decision is choice of the branch. If you are good in coding then go for CSE in MIT else go for ECE in VIT.

It's pretty decent. 26 students from that branch got 10 LPA offer last year.

No, you can't. Lateral entry in not there in VIT, Vellore.

Yes, there are good chances with above 90%.

Yes, there is a good chance as they require more than 90% in HSC.

Yes, it is one of the best colleges for CSE.

VIT-Vellore does not offer lateral entry admissions.

You'll get the withdrawal link here:
vit.ac.in

Vit.ac.in is the website where you'll get the withdrawal link.