JEE Main

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

It depends upon your choice. If you can handle the pressure and study the syllabus with the same dedication that you studied for two years before, then you can take it. Moreover, you need to work very hard as you mentioned you have very less marks in Mains this year.
Also, you can take admissions in private universities, but if you have another chance to prove yourself, go for it.

The admissions are purely on the basis of JEE Advanced. There is a fixed date for the application of IIST out of a limited number of seats, a merit list is prepared and the students are allotted the colleges for admission. Your Mains marks are of no use for admissions in it.

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.

Hello,
I hope you are doing well. You can check the list of colleges including NITs and IIITs that you can get according to your marks and rank. Use Shiksha JEE college predictor:
https://www.shiksha.com/b-tech/resources/jee-mains-college-predictor?utm_source=connect&utm_medium=CR_JEECP&utm_campaign=7489993

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.

Kindly follow my answer on this link:
https://ask.shiksha.com/i-got-12505st-rank-in-jee-mains-do-i-get-seat-in-your-collage-qna-4804605?referenceEntityId=4806933

GRIET takes admissions on the basis of EAMCET, (Engineering, Agricultural and Medical Common Entrance Test) exam conducted by Government of Telangana. Moreover, for the cutoffs for this, kindly follow the link:
http://www.griet.ac.in/eamcet.html

Since, your questions seems less clear, I request you to describe it in a bit more words. Moreover, there is no harm in going through both the counselling. Opt for the best college, by comparing it with from both.