I use Mupen64++ but I wanna know if this emulator is banned

If you are talking about Mupen64plus (android emulator) yes Mupen 64 0.5 rerecording is also allowed

"Emulators used with loading time advantages over "standard emulators" (a/the standard emulator is Project64 1.6) are forbidden." - Quoted from the general rules for SM64 ROM hacks.

As long as the emulator doesn't have faster loading times than Project64 1.6, then it should be allowed.