B.Arch Eligibility

I don't think that B. Arch is there in MNNIT especially at undergraduate level. I can't say clearly about post-graduation. But I strongly think that you have confused between MNIT to MNNIT. So please review it.

Eligibility for the Bachelor of Architecture (B.Arch):
The duration of the course is 5 years and to get admission into B.Arch. The student must be fulfilled the following conditions:
10+2 or equivalent with a minimum of 50% marks along with the compulsory subject of mathematics.
10+3 years Diploma in any stream from a recognized university/ board/ institution.
Cleared NATA (National Aptitude Test in Architecture) with the 80% marks conducted by Council of Architecture.

Here are the subjects of B.Arch:
1. Architecture design
2. Building construction
3. Theory of design
4. History of Architecture
5. Building science
6. Building management
7. Architectural drawing
8. Computer and software lab
9. Workshop practice
10. Architectural appreciation
11. Theory of settlement

You should apply for counseling at MPTE to get the college.

Your JEE marks are quite low and through NDRI exam you can't get into B.Sc or B.Arch in IP, for admission in B.Sc or B.Arch in IP university check out the link below:
https://www.shiksha.com/university/guru-gobind-singh-indraprastha-university-delhi-24725

Yes definitely! you can apply for that.
Don't listen others and try for best.
If you like my answer then raise your hand my making an upvote.
All the best for your bright future.
Good luck!