Question: can kyogre be caught with an ultra ball?
Answer: Timer Balls have the best chance to catch the legendary pokémon, but only if 30 turns have passed in battle. Before that many turns have passed, if you are playing Sapphire, Net Balls have the best chance of catching Kyogre. Otherwise, use Ultra Balls on Groudon until 30 turns have passed, then switch to Timer Balls.