Yeah, you will get another chance to catch Sudowoodo, Raikou, Entei, and Suicune in the Realgam Tower, when you have to defeat Miror B., Dakim, Venus, and Ein to get the ID Badges. However, it would be a good idea to just save your game before you face the trainers with these Pokémon, so you can simply restart your game just in case you fail to snag their Pokémon.