B.Arch

Any student who has 50% marks and above in their 12th exams is eligible to sit for the NATA (National Aptitude Test in Architecture) exam. Student should have Mathematics or Business Mathematics or statistics as a compulsory subject during their 12th boards. Selection is done on merit basis through the NATA exams.

Yes, you can as in India you need to give NATA entrance exam and then after clearing the same you can take direct admission in B.Arch architectural colleges.
But remember that not all colleges accept NATA scores, so you need to choose the college which accepts NATA score with 3-year Diploma score.

Hi Tejas,
Yes, you are eligible to get admission in B.Arch. You need to appear for NATA, but few colleges also provide direct admission in through lateral entry.

Check out the predictor below for details:
https://www.resonance.ac.in/reso/news/jee-main-branch-predictor.aspx

Check out the link below for colleges and filter colleges according to location:
https://www.shiksha.com/architecture-planning/colleges/colleges-india

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

Yes, if you have diploma in civil engineering you can surely get lateral entry in B.Tech architecture but some colleges has some colleges on their own rules. Most universities usually take the lateral entry for civil engineers to the B.Tech architecture you can surely search for that.

Considering you fall in general category, you will get the lower branches in NIT, Allahabad and top branches in NE, NITs and other lower NITs. If you are interested in core branches then better take RV, Manipal or VIT.