Before considering any continuance of your relationship with him I would say that you need to know whether he is out of the religion mentally.
The Jehovah's Witnesses religion has a horrible habit of dragging people back in. Unless he is deconverted, you have a high risk that it could strain your relationship with him in the future.
To reconcile with his parents he has to go back to the religion. If he does that he's going to want to drag you and any offspring (if the relationship goes that far) with him. Or, he could end your relationship in order to go back. Whatever he chooses, it will be turbulent in one way or another
The desire to go back can spring out of nowhere and could happen in 10, 20, even 30 years from now.
The best advice for you is have a little look into the background of the religion before you make any decisions.
If he chooses you over his religion that is his decision. It won't ever be your fault and if he ever resented you for that decision then he would be wrong.
He will have known the implications of dating you in the first place. JWs are very strick on that kind of thing. It's his fault that he is in this predicament.