Could a person with hemophilia b, be an organ donor?

Not a living donor. Unclear whether the query was about organ donation while alive or following death. Since we never want to harm a live donor - who doesn't need surgery, most teams would not put that person at risk for donation of a kidney or a portion of liver or lung. However, if the person with hemophilia has died, multiple organs may well function well enough for txp. We would be grateful for these gifts.
Depends on type. The safety of living kidney donation has been established from a healthy donor pool. Since patients with hemophilia b are at increased risk of bleeding complications from any surgery, most transplant centers would be hesitant to use such an individual as a living donor. However, if one were to serve as a deceased donor, hemophilia b would not be an exclusionary factor.