Heavens forbid, however.......
as a once keen dinghy sailor (Lasers / Mirror / GP 14's / Optimists, Escapes)etc. I've capsized many times. If this were to happen in my RIB apart from getting on the VHF (handheld waterproof) I'd attempt to right myself as follows.
1. Position myself at the bow and take hold of the bow line which would automatically bring the nose into the wind and sea.
2. Run the bow line to what I'd determine at the center of the boat making it fast to either a grab handle / A frame or other secure object.
3. Deflate the tubes on whichever side of the boat I was hoping to right her from, i'e whichever side was going to be immersed as she flipped over. Deflation would assist with the boat digging in !
4. Climb atop of the upturned hull with heaving line in hand and as with a dinghy use ones weight (and additional crew if avalible) to heave her over.
However, just attempting this with one of the aforementioned small/light and balanced craft with a keel / daggerboard to stand on is task enough on a calm day. Somehow I fear given the circumstances that may flip a rib, I doubt whether I'd manage to get mine back over.
Hence, quality safety gear, preperation and the awarness of what could happen are key to surviving any such events.
Buy it & Use it, then sell it and buy something bigger