Hello!!
Thanks for contacting Careers 360 hope we will help clarify your doubts.
If your rank is in top 500 then you can easily get an architecture seat in top NITs like SPA Delhi,NIT Trichy

The cutoff for B.Arch courses is about 50% of the total marks.

Above 70% and you can get a seat in one of the finest institutions in India offering B.Arch.
You can see the previous year cut-off's-

https://www.google.co.in/amp/s/engineering.careers360.com/articles/jee-main-cutoff-for-b-arch-b-planning%3famp
Good luck.