B.Arch

No, this year, Manipal University is not conducting any exams for b.arch course, the merit will be on the basis of your 50% NATA score and 50% 12th result. They are conducting MU OET exam only for B.tech course.

Please use Shiksha's college predictor:
https://www.shiksha.com/b-tech/resources/jee-mains-college-predictor

To get admission in top government colleges, you should have more than 120. And to get admission in private colleges, you should have a minimum of 70 to 80 / 200 in NATA entrance exam.
Good Luck!

Admission is through counselling conducted by Directorate of Technical Education, Maharashtra based on marks obtained in 10+2/ Diploma and score obtained in National Aptitude Test in Architecture(NATA).
Selection parameter and weightages:
10+2/ Diploma marks - 50%
NATA score - 50%
For further details regarding eligibility and selection process for this course from Sir J.J College of Architecture please refer to the link provided below:
https://www.shiksha.com/architecture-planning/course/b-arch-sir-j-j-college-of-architecture-mumbai-71170

Hi,
Minimum Eligibility to Apply: 12th - 50%
Additional Details
Mandatory Subject : Mathematics
Entrance exam: KEAM/NATA
Other eligibility criteria
Candidate must have passed three years diploma and secured minimum 50% marks in aggregate with Mathematics as a subject of study at 10+2 level or
Passed International Baccalaureate Diploma, after 10 years of schooling, with minimum 50% marks in aggregate and Mathematics as a compulsory subject.

Yes you can apply for B.Arch.