How long do I have to wait before I can get hair transplant over a recently excised 0.6 cm pox scar in my cheek?

Wait at least six months before transplanting a pox scar so that everything is healed before going forward with a hair transplant into the cheek. For a POX scar, Scalp MicroPigmentation is similar and faster with the results and probably much less expensive, see below. The picture shows a thumb size scar which was not transplanted but covered with Scalp MicroPigmentation, much smaller than the POX scar to which you are referring.

https://scalpmicropigmentation.com/scar-covering/

https://scalpmicropigmentation.com/wp-content/uploads/2016/04/scalp_micropigmentation-new_hair_institute-147-scalp_scars.jpg