Hello Aspirant,

I hope you are doing well.
You can refer to these books given below :

NATA & B.Arch Question Bank by Ar. Shadan Usmani.
NATA & B.Arch complete self study material: entrance examination by Ar. Shadan Usmani.
A Complete Self Study Guide for B.Arch by P. K. Mishra.
B.Arch Entrance Examination Guide by Surendra Kavimandan.

Even though not secure with available books for JEE Mains paper 2, however, I can incorporate the accompanying valuable blog connects that could help you get downloadable materials just as for online investigation

Likewise, you can get the valuable materials and study points here in this page - Resources for JEE Mains paper-2 (B.Arch/B.Planning)

You can get the total rundown of prospectus here - JEE Mains Paper-2 (B.Arch/B.Planning) Syllabus

Likewise, a similar blog can be useful for NATA too except that the Math and sketch part isn't relevant! check the fundamental contrasts in the prospectus.

You needn't bother with a book to get ready for NATA or Mains Paper 2 as long as you are great at Mains level maths and drawing.

The inquiries are for the most part IQ based and you needn't bother with much profundity information of anything for giving NATA or Mains Paper 2.

You may allude my following response for Mains Paper 2:

Pushkar Kale's response to Joint Entrance Examination (Main): How and what would it be a good idea for me to get ready to split JEE Mains second paper (design)?

On the off chance that you are truly keen on giving NATA, you may allude following book Amazon.in: Buy A Complete Self Study Guide For B.Arch 2015 Book Online at Low Prices in India

I hope this helps.

Good luck