In injury, when and how is nasal cartilage reset on bone after rhinoplasty if bones do not break?

Unfortunately, this is a difficult situation, as your surgeon did the right thing by not operating immediately.  Depending on the actual damage to the cartilage, we can sometimes place splints internally and externally to help shape the nose.  In many cases, we just have to wait for the nose to fully heal, and repair it at 9-12 months.

Trauma to the cartilage is more difficult to manage than bone.  Bone can usually be reset or "popped" out into position.  Your siutuation sounds as if the cartilage tore loose from the nasal bones, causing them to collapse.  The repair usually requires suturing and spreader grafts.  Your doctor did the correct thing by waiting.  Nothing can be done in the short term other than a wait and see approach.  The spreader grafts are usually harvested from the septum.  The operation has about a 5-7 day recovery.  Good luck in your recovery.