JEE Main Paper II & NATA both are the National level exam for the admission to B. Architecture programme. As per the eligibility to apply for JEE Main paper II Entrance Exam, You need to have PCM mandatorily in your 10+2 or equivalent exam with minimum 50% marks in aggregate and 50% individually too.

To apply for NATA also you must have passed 10+2 exam and scored minimum 50% marks in Physics, Chemistry and Mathematics and also in aggregate. You can check the further eligibility to apply for teh exams with the given below links.

https://engineering.careers360.com/articles/nata-eligibility-criteria

https://engineering.careers360.com/articles/jee-main-eligibility-criteria

You can also apply for your state level Entrance Exam to get admission for B.Arch programme.

Good Luck!