I might make a custom console and I want to remake this game WoolCat 3D - Speedrun for it. Could i still submit speedruns for it?

Custom... console? Huh?

Guessing the answer will be "absolutely not" but you're gonna need to be a lot more specific about what exactly you're doing. Also, for future reference, questions about a specific game should be asked in the forums for that game, every game has its own rules that are specific to that game.

Edit: Oh wait, you're one of the moderators. Up to you/the other runners to decide if whatever you're talking about makes sense, I guess.

Im trying to reright that game to an arm64 platform

Yesss!