You should definitely choose NMIMS Mumbai. A number of people would be of the opinion that XIMB HR is good but the change in the brand name from XIMB HR to XaHR has adversely affected the placements and compared to this, NMIMS Mumbai HR is growing extremely well in the case of placements.
You can compare the two colleges on the following points:
A lot of the current XIMB HR students will advise you to not go for XIMB HR. It does have lower fees but NMIMS has many more advantages that offset this parameter. Overall, NMIMS has many better profiles to offer as compared to XIMB.
If you are stuck in this dilemma, you should surely go ahead and opt for HR at NMIMS Mumbai.