B.Arch

Apart from that, you get a lot of books online, I'll list a few of them:
NATA & B.Arch Question Bank by Ar. Shadan Usmani. NATA & B.Arch complete self-study material: Entrance Examination by Ar. Shadan Usmani. A Complete Self Study Guide for B.Arch by P. K. Mishra. B.Arch Entrance Examination Guide by Surendra Kavimandan.

VIT-Vellore, SRM and IPU are the most reputed universities in India for B.Arch.

You may get a seat in the 4th round of counselling so keep active in the JMI counselling procedure.

First of all, your JEE Mains score is not sufficient to get admission in a good government college. You can take admission in top private colleges like VIT, SRM, etc.

Yes, that's true. The classes will start from 1st August and there will be really few students as Jamia will probably release 1 more list, that is, the second list.
But don't worry, no such studies would be conducted. The classes will be a time pass as the teachers will try to stretch them till August end. The admission finishes fully in the first week of September.

Hi,
Admission in Rizvi College of Architecture for B.Arch will be made through CAP based score obtained in National Aptitude Test in Architecture (NATA).
https://www.shiksha.com/architecture-planning/course/b-arch-rizvi-college-of-architecture-bandra-west-mumbai-26299

It is not advisable to pursue distance learning programmes for technical fields like engineering or architecture as they should be performed practically and are more of experience-based, so better take up a classroom programme.