Hi

NATA is conducted by the council of architecture and is mandatory for admission into first year B.Arch courses across all the colleges and institutes in India.

Whereas JEE (AAT) is conducted by national testing agency and is mandatory for getting admission into B.Arch program offered by IITs.

https://jeeadv.ac.in/aprogrammes.php

https://jeeadv.ac.in/pinstitutes.php

Various Institutes of architecture across india have eligibility mentioned as NATA/JEE. While IIT has only JEE mentioned in their criteria. Moreover it is mandatory to clear both JEE mains and JEE advanced for getting into IITs for B.Arch.

NATA is widely accepted by colleges offering this programmes whereas AAT is an entrance exam for admissions to architecture programmes offered by the Indian Institutes of Technology (IITs).

So it depends on where you want to apply or get admission into so choose accordingly.

More on NATA

https://engineering.careers360.com/articles/nata#-----NATA-2021-Eligibility-Criteria---

More on JEE

https://engineering.careers360.com/exams/jee-advanced

Hope this helps.