It is probably a ring. Sockets usually are on a ring (but not always), and the fact that you have 2 cables means it almost certainly is. It's relatively easy to check - unplug or turn off any large loads (e.g. electric heaters, kitchen appliances on the ring), turn off the circuit by switching the breaker or removing the fuse, remove the wires from the socket, make sure that they aren't going to touch anything they shouldn't (temporarily putting them each into their own 3-strips of choc-block might be a good idea), turn the power back on, and use your multimeter (which of course you do have, don't you, as it is as essential a tool for working on electrics as a screwdriver is) to check that both live conductors are live. If they are, it's a ring, if they aren't then it's a damaged ring, or a radial, or a dodgy spur.
But now we come to something which worries me, which is that you don't appear to know how ring mains are wired, as you're talking about junction boxes, and an extra three cables. This is not the way to do it.
Do you actually know how ring final circuits are wired?
Should you be doing this yourself, or should you be getting an electrician in?
Also - what sort of room has only one socket? My immediate reaction is that unless it's a very small bedroom the wiring dates back many years. Do you know how old it is?
PS - why is it that whenever I am crafting a reply, breezer always nips in first whilst I'm still typing?