JEE Main Paper 2 is conducted for admissions to B.Arch/B.Planning courses at NITs, and other Centrally Funded Technical Institutions. JEE Mains paper 2 is based on both drawing and maths skills , it has a math section (level is same as the jee mains paper 1) and a sketching and 3D interpretation section. The rank you obtain in paper 2 is independent of the paper 1 rank.
NATA a is national level exam for admission into Architechture field. If you want a good college in India, you should apply for that. Or, you can apply for JEE Mains Paper II. It is also an entrance for B.Arch course. Other entrance exams are either state level or university level. So, it depends on you.
Hope it helps. All the best!!