Only homebrew that supports the adapter right now is Nintendont.
Yes, you can. But you can only play 32mb N64 Games, you need to change the rom on Ocarina Of Time Master Quest For Gamecube. And the Official N64 Emulator for Gamecube will do all.
(Of course, loading the rom with nintendont)
You can also try changing the rom in Mario Kart 64 for Gamecube or Super Mario 64 for Gamecube. These games uses Ocarina Of Time Gamecube ROM for that.
KADE has a device on the way that will convert controllers like n64 to show up as a classic controller.
https://twitter.com/kadedevice/status/544209427843133441-