The latest version released is WTOS 7.0.0.30, version 6.5.0.30 is the latest version released (for the 6.5 series) but not the latest version with all the hot fixes (not sure but it could be 6.5.0.41).
If you have a maintenance contract you can download this version, if you don;t have any i would advise you to have one (it’s very each).