RPG paper maker? Pode ser utilizado? (RPG paper maker? Can it be used?)
E sobre a tradução do jogo? Em quais línguas devem estar? (And what about the game's translation? Which languages should it be in?)
1) Yes, it can be. It's in the FAQ on the jam page:
Games made in any version of RPG Maker or similar engines are preferred, but you can use other game engines. However, in that case, additional limitations apply.
What does that mean? If you use RPG Maker or an engine similar to it (such as WOLF RPG Editor) to make your game, then you are free to just make a horror game. It doesn't matter if it's a puzzle game, a dark fantasy RPG or a Visual Novel made with a ton of custom plugins. All is fine and well, so long as it's a horror game or at least features significant horror elements.
If you use a more "heavy-duty" engine such as Unity, Godot or Unreal Engine, then you need to make sure your game "keeps to the spirit of RPG Maker Horror Games". This is very open to interpretation and is judged on a case-by-case basis. Your game should most likely be 2D and top-down/side-view at the very least. The assumption is that if you are using a different engine, you are already familiar with RPG Maker-style Horror Games and how they normally are. We tend to give people the benefit of the doubt when it comes to this.
2) It would be for the best for your game to have an english version, so that most people can play it, but it's not required.