The port on the IIc is only physically the same, AFAIK it won't work with much other than the mono LCDs that were available for the IIc.
It's worth noting that while the RF adapter uses an RCA cable, it doesn't output a composite video signal like you would use on a modern TV or Apple II composite monitor... it's meant to be used with one of those old "game/tv" switches that screw onto the antenna terminals. They do work quite well, in my experience, and have the advantage of also conveying the audio signal to the TV set.