Exam

Yes, you can go. They just need your rank in VITEEE but not JEE main.
As you've a good rank in VITEEE, you'll get the branch of your choice.

No, only after qualifying in NATA 2019 exams a candidate can fill the admission form for it be valid. Only candidates who have the following credentials shall be eligible for admission to B.Arch. Course. I. Qualified through the recognised aptitude test in Architecture NATA or equivalent) in 2019
ii. Have gone through any of the following curriculum with marks as prescribed below: (a) Secured 50% marks in Physics, Chemistry and Mathematics and also 50% marks in aggregate at
10+2 level examination.

There is a chance to get this but branch is not known.

Admissions of private management seats have started after the result of NATA 2019 exam 1st round. After NATA 2019 exam 2nd round there will be a lot of government merit seats available.

Generally, if you are a top 20 ranker, you will get to choose some top colleges/universities in India with fellowship. In order to get a good college you will have to be among the top 50 rankers.

Hi Udit, as you have scored 91% in class 12th board and if you are interested in automobile engineering then Amity University will be a good choice for you. Colleges matters, but not 100%. If you are hardworking and punctual, then you will make your path to any college. From Amity, you can expect a good placement.
Best of luck.

Hi, for what college are you asking for? Visit this link to check B.Arch colleges based upon your rank:
https://www.shiksha.com/b-tech/resources/jee-mains-college-predictor?utm_source=connect&utm_medium=CR_JEECP&utm_campaign=6919840
Then visit this link for various colleges which provides you brochure:
https://www.shiksha.com/architecture-planning/colleges/b-arch-colleges-india. Check the link below to get a list of approved Architectural Colleges. https://www.coa.gov.in/index1.php?lang=1&level=0&linkid=25&lid=26.