This game is a fan-made ROM hack, and while it introduces many new Pokémon and features, it does not include Latios as a capturable Pokémon.
If you are looking for Latios, you would need to play the official Pokémon Ruby game. In that game, Latios can be encountered in the following ways:
* Eon Ticket Event: This is the most common way to get Latios. You would need to obtain an Eon Ticket from a special event or through trading, then go to the Southern Island to find Latios.
* Random Encounters: There is a small chance of encountering Latios in the wild, but this is extremely rare and requires specific conditions.
Keep in mind that the Eon Ticket event is no longer available for the original Pokémon Ruby game, making it very difficult to find Latios in the original game unless you can find someone with an Eon Ticket to trade with.