Work 9 rows of k2p2 rib.
When it says "Rib 6..." it means to continue with the rib pattern as you have been doing. If that's k2p2, then that's what you should do. Usually these directions are used when the pattern isn't sure where you are in the rib stitch (perhaps because there are directions for different sizes) so instead of specifying k2p2 or p2k2, it just says rib 6, rib 1, or rib 4. The impostant thing is to work the ribbing so that it matches the previous rows as much as possible (even the increase here will flow with the rib pattern).