Hello, I speedrun Mario on the Nintendo Switch. Is it legal to use a pro controller, or do I have to use a NES Controller?

you can use it im pretty sure. you just cant press L + R or use turbo buttons

Pro controller is fine.

is able to play on emulator with ps4 controller connected for bluetooth ?

You can play with any controller you want as long as it doesn't allow turbo or L+R

no my controller is configurated to not have turbo

@xXJulianbrito_TYXx3 If you're able to plug it in via USB, I'd definitely recommend that over bluetooth.
Bluetooth is fine for regular gaming, but the latency difference is absolutely noticeable in a run like SMB.

ok thanks and please check my runs and is connected for bluetooth

Thank you all for answering so fast! Would I be allowed to reconfigure my buttons so that Y is B and B is A

Pretty much whatever you want except anything that gives you a categorical advantage, such as turbo or a+b, or any custom macro

Just double checking, an NES to USB adaptor for an origonal NES controler would be perfectly fine?
Edit: Just to clarify, this is in order to play on a EmuHawk emulator on my pc as i cant get an NES but can get a controler

The official stance is that we don't really care what you use as long as you're not using functions that you can't do on an original controller: turbo, the ability to press both Left and Right at the same time, etc.

NES controller to USB adapter? Sure.
Dance pad? Sure.
Guitar Hero controller? Sure. (I have actually seen this done)
SNES controller? Darbian used to do that I'm pretty sure.

Is a switch pro controller/ joy cons acceptable?

ok thank you sry I didn't see it