If you are wondering whether work experience is mandatory to be eligible for NMIMS Mumbai, the answer is no, it is not. All you need to be (or about to be) is a graduate with a full-time degree of 3 years or more.
While having work experience can give you a slight advantage, as it is a part of the evaluatory component for the final admission score, it only accounts for a mere 5%. So, don't worry too much about it. You can always compensate by performing well in your NMAT and CD-PI rounds.
For your convenience, here are the APPROXIMATE (not official) proportion of the different factors that NMIMS considers for their final admissions:
As you can see, there is always some space for you to outperform and make up for any concerns you have within these parameters. So, focus on preparing well for your NMAT and showcasing your skills during the CD-PI rounds.