I plan on getting Rhinoplasty/Septoplasty, will I be able to train Brazilian Jiu Jitsu again?

This will depend upon the maneuvers employed and your healing.  You will need to ask your surgeon.Find a board certified plastic surgeon who performs hundreds
of rhinoplasties and rhinoplasty revisions each year. Then look at the
plastic surgeon's website before and after photo galleries to get a
sense of who can deliver the results. Kenneth Hughes, MD Los Angeles, CA

Dear Tzee,If you will be doing Augmentation Rhinoplasty using implant, please allow at least 3 months before getting back to training. For Reduction Rhinoplasty, a shorter time of 6-8 weeks will be needed.

You should be able to resume full physical activities after 6 weeks.  Your nasal bones will be very solidly fixed at that point.  You might have residual nasal congestion from any internal work performed.  Of course, your healing will definitely be related to the scope of surgery performed.