Which would be better? NMIMS Mumbai BBA or IIM Rohtak IPM (exit after 3rd year with a BBA degree)?

IIM Rohtak is better if you want to join IPM there and graduate with a BBA after three years.

A BBA from IIM Rohtak is unquestionably more valuable than a BBA from NMIMS, Mumbai because the course curriculum and pedagogy are superior at IIMs, which use a trimester system rather than the traditional semester system used at NMIMS.

The placements will be similar between the two. However, NMIMS wins because, with only a BBA, you'd have to apply off-campus if you wanted to be placed at IIM Rohtak, as there are no placements for BBA students.

Keeping everything in mind, you should prioritize IIM Rohtak over NMIMS because of the IIM brand and because it is a less expensive option. At the end of the day, you still have the option of pursuing an MBA at IIM Rohtak, which you do not have at NMIMS, and CAT can be quite unpredictable and difficult.