RCA sockets are only 2 wire and, hence, only one way. If you buy a two-way box it will have two sets, one in, one out.
Check the specification for the TV scart socket, it will undoubtedly be two-way (for recording and playback on a VCR). Scart sockets with 6 RCA phonos for in/out, or 3 with an in/out slider switch, only cost a few pounds from somewhere like Maplin.