Yes, DU JAT is for professional courses like BMS, BBE and BBA.

But if you want to go for courses like BA(Hons)Humanities and Social Sciences/BA Multimedia and Mass Communication /NEd/BEd Specialisation in Education/BEIEd/BLISc/BPEd/BTech/Fine Arts(UG)/Five Year Integrated Programme in Journalism and some specific post graduation courses, You have to appear in DUET (Delhi University Entrance Test).

You can also appear in both the Entrance depending upon the course you want to pursue.

I hope this helps.

All the best.