Engineering Entrance Exam

No, but you won't be able to get a seat in NIT. Moreover, trying for lower NITs with some unknown branches is not worth.
Kindly go for private colleges, universities or try for a year drop.

Below is the link to official cutoff marks for GRIET branch-wise. Kindly make the decision accordingly.
http://www.griet.ac.in/eamcet.html

yes you can get this college at this rank but not gov you can only get private average colleges

Hello, hope you are doing well. No you are not eligible for NIT in architecture with 35146 rank.
Go for government college you will definitely get one. Else Nirma University, Symbiosis, IPS Indore, CEPT University, MS university are some good colleges for architecture you can also take admission in this colleges.

For getting into VNIT CSE, you should be having around 215-225 marks in general. Since these marks are low, but yes, the cutoff for this year has fallen down for Mains due to tough paper than actual expectation. Best of luck.

Since, you have not cleared any cutoff, it would be not possible to get the mentioned rank. Kindly mention the actual marks to get the precise and best support. Moreover, with this marks you'll not get any government college and with this rank too.

Both branches are equally important and good. It depend on your interest. Moreover, if still you have to choose keeping in mind your aim to prepare for the civil services exam, I would suggest you to go for mechanical as a backup option.

Hello,
I hope you are doing well. No, you are not eligible for NIT with 147 marks in JEE Paper 2. Go for government colleges or some private college like DY Patil College, Nirma University, IPS Indore, MS University. You will definitely get colleges with these marks but you are not eligible for NITs.

Yes, you'll easily get NIT Silchar with your desired branch (probably CSE).
Best of luck.

Assuming you are from general, you'll not be able to get a seat in CSE or IT or such core branches in DAVV since this is a government college. Colleges prefer to have vacant seats rather than to have students with lower marks than their cutoff. Moreover, you can also prefer good colleges such as Acropolis, Medicaps etc.