The effective rules are those of the tournaments organized by the Game Editor, Riot Games.
You can find here the additional rules of the league and the process :
https://drive.google.com/drive/folders/1d2Z6obd5L5EQP1A78DnzZKz84yIw9HX0?usp=sharing
Règlement et déroulement en français accessibles ici :
https://drive.google.com/drive/folders/1HaZbskCDNKYU4CZ0OmtwlCa5Dby-h-_q?usp=sharing