Vellore Institute of Technology - Chennai Campus

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.

Yes, you can easily get CSE in the Chennai campus. According to me, you will be getting seat in the 2nd or 3rd category.

Obviously, your placement process will start in the final year of your course.

Yes, you may get it. CSE would be very tough, but for ECE, you have high chances.