Can i speedrun and submit my speedruns with Nintendont or any other option? I wanna play Luigi's Mansion but i dont have the official disk, i dont know if i can play in Nintendont (or another option if is recommended)

From the official rules: You may load your disc using homebrew applications as long as they do not affect the load times of the game. If you are unsure about what applications are allowed, ask a moderator.

For NTSC, you must use programs like Priiloader, Gecko, or Swiss to boot the disc. Nintendont is allowed for all PAL categories, but you must own an official PAL disc.

If you get a time over a certain threshold, Runs done on Nintendont or Dolphin are allowed, but it must be marked as an Emulator, as Nintendont emulates the console region and removes lag. If you get a time lower than said threshold, you must own an official disc and run it through one of the programs mentioned above. Each category has a certain threshold, so check the category rules to find it.

If you still wish to run on Nintendont or Dolphin after getting a time lower than said threshold, you may submit to the Emulator leaderboard in the Category Extensions. (Applicable for Any%, Any% No OoB, and 100%)