For 6mm2 T&E, I might most likely use different 20mm oval conduits, a person for each of the two cables, but I might guess you would need 32mm oval conduit it you actually wanted to put each in one size. Cable drawn nicely of the reel will press down conduit https://ovalconduit03456.targetblogs.com/29586737/a-review-of-oval-conduit