Is FCEUX an approved emulator, if not, what are some approved emulators

Yes FCEUX is approved. From the rules the allowed emulators are Nestopia, FCEUX, Bizhawk and OpenEmu - Frontends such as RetroArch are not permitted.

Why is retroarch banned?, i downloaded it before seeing this so what should i do? the emulator says "retroarch Nestopia" nestopia is allowed so what does this mean, if i need to use another emulator what would you suggest

RetroArch is a front end emulator which would provide an unfair advantage to this game which can’t be duplicated on original console. Nestopia by itself is perfectly allowed as long as Retro Arch isn’t being used to run the emulator. A list of all the approved emulators are listed under the rules tab. If it isn’t listed, it isn’t allowed.