Rainbow Six Siege has a system of Seasons, which are major game updates that focus on improving the experience. Each Season includes new free content such as maps, features, game modes, and new operators. According to the search results, Rainbow Six Siege has had 29 seasons in eight years, and the game is currently in its twenty-ninth season, Operation Dread Factor, which is the second season of Year 8. The current season is expected to end in late August 2023. Therefore, as of September 22, 2023, we cannot determine which season Rainbow Six Siege is currently in, as the search results do not provide information on the start date of the next season.