What is the normal treatment and recovery rate for brain damage in an otherwise healthy 16 yo male?

Many variables: Many things go into treatment and eventual recovery . How severe was the damage. Was it just one incident or repeated insults like concussions with sports. Was person in coma for a prolonged period. Initially treatment is brain rest - that's why sometimes they induce a coma to let the brain rest. Next is evaluation for residual deficits. Then is retraining the brain to overcome the deficits found.