Do I have to wait six months to account for a potential root canal before getting a crown?

I don't see a reason to wait.  Perhaps see an endodontist to evaluate the nerve.  If it needs to be done go ahead and do it.  If not, have the crown completed.  Good luck.      

A consultation with an endodontist would be a good first step. You can have a permanent crown done sooner than 6 months as long as you understand that you might need a root canal in the future and that it could shorten the life of your crown.

Hello,
If your doctor want to wait more time before decided do a root canal is for one reason because when you need it you dont have to wait ask your doctor why is waiting that time. 

It's always best to do the root canal before placing crowns. You can do the root canal through the crown, but that will compromise the integrity of the crown and could cause it to break. I usually give trauma cases 6 weeks to heal before doing anything permanent. Then we retake xrays and test the nerve before deciding on a course of action.