From doing the RMS on mine and wanting to not use RTV on it - but then needing to take the oil pan off one or two more times to chase small leaks, I'd say both sides.
I am very tempted to say - lay a bead on both sides ALL THE WAY AROUND. Your call if you'd take this "full bead" suggestion. Good for leak sealing - not so good for the next time the pan needs to be removed / cured RTV removal.