Vellore Institute of Technology - Chennai Campus

Vit is a good university and has high credentials. It has got a good name and prestige. The market must have a good value of the same and also you should be getting a good placement with the vit tag on your degrees

According to your rank, you will easily get VIT-Vellore in the 2nd or maximum in the 3rd round. Suppose, if 1% you didn't get Vellore then you will get Chennai easily, but I would suggest you be focused on Vellore and don't try to go with Chennai campus of VIT.

Vellore and Chennai have common placements.
Placement record is good, almost everyone gets placed. There are people who go at 18L per annum also. You can find a lot of people going at 8-15L as well. Most people get placed in the 5-8L bracket. Mass recruiters pay less and people joining those get around 3-4L per annum.
We have big 4 that come every year.
Companies like GE, Suzuki, Cisco, TI, NI, Intel, Microsoft are a few I can remember as of now.
IT companies like Wipro, Cognizant and Infosys come to campus.

So I believe in terms of education both VIT Chennai and Vellore impart the same. However, Chennai has a better student to faculty ratio and so you would have more opportunities to do something rather than just get lost in the crowd. Placements are joint so that won't be an issue. Generally when people decide between Vellore and Chennai with a branch like ECE it comes down to:
Vellore is a bigger campus and has grander fests. Chennai is a metro city and has better facilities. Rest assured the VIT Brand name will be evident in both the campus.

Don't take civil through management quota, as there are no placements in civil branch.

You can get any branch in VIT-Chennai campus.
For Vellore also, you can get most of the branches (maybe except CSE).
Yes, you can also get ECE in Vellore.

It's of no use to take civil through management quota, because there is no placement for civil branch in VIT Chennai.

I don't think so, but if it shows that you are eligible for the counselling, then it depends on the availability of the seats.

You'll be getting your placements only in the final year and not before it.