Having friends in both institutions, I suggest you to go NMIMS Mumbai. XIMB HR has recently switched their name from XIMB to XaHR. This cost them a lot in terms of placements. All of the companies, instead of reaching out to XIMB are showing up at NMIMS Mumbai boosting their demand day by day. 

If I were to compare both the colleges based on certain parameters, I would say:

• Batch: The batch size at NMIMS is 60 which are admitted on grounds of strict merit. On the other hand, XIMB takes in candidates on reservation grounds. 

• Location: If you have decided to reach Mumbai for your MBA, no doubt that it is indeed the best place. NMIMS provides better corporate interface and project opportunities. 

Placements - 

Some of my friends who were on the wait-list of XIMB decided to switch to NMIMS eventually. And some of them withdrew their names from the wait-list just to reach other colleges (these were in the lower-tier) but not XIMB. Even the students who are already studying at XIMB advise others to not reach there.