Ruling

[Marroy]

Play off tee not sure where ball went play provisional find first ball but have to take an unplayable where do I play from

 

[Colin L]

See Rule 19. Provided your ball is not in a penalty area, you can play from any one of three places: within two clublengths of where your ball lies, not nearer the hole; back on a line from the hole through where your ball lies, not nearer the hole; or from anywhere in the teeing area from where you played your tee shot, teeing your ball up if you wish.

 

[salfordlad]

A possible (less likely) read of the OP is which ball to play also. That issue is very clear under the rules, that provisional ball cannot be played once original found and it must be proceeded with under the rules - Colin details the way forward.