Bridge Gap Broken Rib Cartilage?
Without the benefit of pictures or an examination, it is very difficult to give you sound advice. Rib cartilage might warp but is doesn't usually break. I am not sure what is causing the gap but it would be nice to see a picture.
Consult your surgeon.
The use of costal cartilage to reconstruct a nose requires a longer healing period. I would be patient and reassess the result with your surgeon.
Wait for final healing
Without a photo it is difficult to discern what you mean by a gap, but it's likely too early for a rib graft to warp. It's possible you might be feeling the edge or end of the graft. Be patient, waiting at least 6 months, to determine a final outcome.