B.Tech Civil Engineering

After your B.Tech in civil you can pursue M.Tech specialisation in structural engineering. It is the better option to do Diploma in architecture.

B.Tech is through RKDF University. FEES is 70,000 per year. Duration is 4 years.
HSC (PCM) is required. If HSC with PCM is not there then you can do Diploma in Civil Engineering. It will be 3 years course. Fees 50,000 per year.

Most of the state government colleges and some universities are also offering admissions through lateral entry. Some of reputed universities/colleges are Jamia, Thapar, SLIET, PEC-Chandigarh, GNE-Ludhiana, IPU-Delhi, etc.

Yes, you can get admission to JSSATE Noida after Diploma but you have to write the UPSEE exam for lateral entry and need to score decent rank. After that, you need to apply for counseling and wait for the result of counseling if you are allotted JSSATE than you have to visit the college to submit the fee and documents. After that, you will be directly admitted in the second year of B.Tech. I wish you good luck!

Check this webiste for eligibility criteria: http://bitsadmission.com/hdmain.aspx#eligibility
A Minimum aggregate of 60% in the qualifying degree examination for All Programmes. So you are not eligible as per the criteria.

Yes, you have to give MHT CET to get direct second-year admission in Sardar Patel College of Engineering for B.Tech civil engineering, check the details below:
https://www.shiksha.com/b-tech/course/b-tech-in-civil-engineering-lateral-entry-sardar-patel-college-of-engineering-andheri-west-mumbai-288316

I am a student of ICFAI University, Dehradun. The eligibility for B.Tech (lateral entry) is either you have completed the Diploma course or you are in the last year of Diploma with 50-55% aggregate in any one of the following branches:
Civil Engineering
Computer Science and Engineering
Electrical and Electronics Engineering
Electronics and Communication Engineering
Mechanical Engineering
Mechatronics
Mining Engineering