In your client folder (the folder you use to start the game) your client file name should say something like 2018-03-07bRagexeRE (with whatever date your client is) unless it was diffed and was put another name instead of the actual date of the client.
edit: I forgot you can also check your client version in one of the servers (char/login/map) I forgot which one though, but it should say something like, "LOADING PACKETVER: 20150512" (with whatever date your client is)