6Rs had 636 From 02 till 07.
The Limited production 6RR was 600. But in 07 They are only offering the (6R)
Also starting 07 they took the CCs back to 600.
So:
02 - 6r - 600cc
03/04/05/06 - 6r - 636cc
05/06 - Limited 6rr - 600cc (due to class restrictions for racing)
07 - 6r only - 600cc