Architecture

Yes, that helps in getting admission easily.

You can do it, if you have the required subjects which includes Chemistry in one of them.

Yes, NATA is compulsory for admission into any private architecture college.

Top 5 architecture colleges with affordable fee structures in India are mentioned below:
1) School of Planning And Architecture, Delhi
2) Indian Institute of Technology, Kharagpur
3) Sir JJ College of Architecture, Mumbai
4) Birla Institute of Technology, Mesra
5) Jadavpur University, Kolkata
Regards.

Please refer to the link provided below for details regarding the admission process for a course in Master of Urban and Regional Planning from The Maharaja Sayajirao University of Baroda. You should be able to download college brochure which contains guidelines to apply for the entrance test conduct

Mentioned below are the institutes accepting JEE Mains paper 2 score:
Indian Institute of TechnologyRoorkee
Indian Institute of TechnologyKharagpur
Maulana AzadNational Institute of TechnologyBhopal
National Institute of TechnologyCalicut
National Institute of TechnologyHamirpur
MalaviyaNational Institut

Now a days, engineering is losing their glory, because of less job opportunities and more crowd that is why this is not a safe side to go, if you are unable to get admission in IIT or any reputed college of India, so I suggest you to go for B.Arch.

NITs are the best option, if you want to do architecture and having a low fee structure. JEE Mains paper 2 can allot you the NITs for architecture.

Please refer to the link provided below for a list of all courses offered by Interior Design Academy (IDA, Bangalore), Indiranagar.
https://www.shiksha.com/college/interior-design-academy-ida-bangalore-indiranagar-35365
M.Sc in Interior design would be feasible if you want to learn different advanced