NATA

Hello Lasya,
The Council of Architecture (COA) will declare the NATA 2017 result on June 10 2017. The website is www.nata.in
The NATA (national aptitude test in architecture ) exam is conducted for admission into B.Arch courses. You need to score at least 80/200 to get admission.

Yes, there are some good colleges for Architecture which are giving admissions without JEE and NATA. And one can join Architecture after 12th Commerce also.
Tell me in which state are you looking for Architecture?

A rank under 1500 will be considered safe to get a seat in RV College for B.Arch in NATA. You have to get a score of about 300 or 300+ in JEE part 2.

You can try for NITs. There are many NITs that provide an undergraduate degree in architecture. So, try out for NIT Trichy, Calicut, Patna, Raipur and Hamirpur.
Other than these, you can apply for SPAs.
SPA, New Delhi
SPA, Bhopal
SPA, Vijayawada
There are other reputed colleges:
J.J School of architecture, Mumbai
Manipal School of Architecture & Planning, Manipal
Chandigarh College of Architecture, Chandigarh

Hello Alatish,
The link below gives you the list of colleges that accept NATA exam scores for B.Arch admissions:
http://www.motachashma.com/articles/nata-participating-colleges.php

Yes, you can. But, only in NITs. It also dependent on your category. And, if you are physically handicap, then the chance increases.

Hello Prashanth,
The minimum marks to get qualified in NATA exam is 80/200 that is 40%. If you get this score, then you are eligible for getting admission in Architecture courses.
But, if your score is very high like 150,160 or above, then you can get the top colleges for architecture like J.J College of Architecture, etc.
All the best.

Hello Brunda,
The admission into Sir J.J College of Architecture is primarily based on the NATA scores only, but on their official website, they have also mentioned about the JEE score card. so I think they admit students based on both NATA and JEE Mains Paper 2 scores. For the details regarding admission and the enclosures refer:
http://www.sirjjarchitecture.org/admissions.html
On this website, you will get a PDF document which gives you the details of B.Arch admission through both NATA and JEE Mains Paper 2.