Players can also cheer each other on during Tera Raid battles, and certain cheers will provide buffs for your team’s Pokémon in battle. Upon beating a Terastallizes Pokémon, you can try catching it with your Poké Balls. Whether or not you catch it, a victory will still grant you various rewards.
Conquering Tera Raid battles is no easy feat, and it’s not as simple as going in with a Pokémon with really high stats. It’s important to consider Pokémon types on both yours and your opponents’ side.
Source: https://www.distractify.com/p/best-tera-raid-pokemon-scarlet-and-violet