JEE Mains Paper-2 is taken by candidates applying for B.Arch in IITs, NITs, CFTIS, etc whereas NATA is recognized by other universities including some government and private institutions. Also, NATA is comparatively easier than JEE Mains even though both have the same syllabus. JEE Mains accepts candidates from any educational degree with PCM as a stream however NATA doesn’t accept candidates who have completed just a diploma.