IRL international games don't tend to happen if you are referring to that, but yes the osu! supported events are the World Cups for the 5 gamemodes they showcase (osu!, osu!taiko, osu!catch, osu!mania (4K) and (7K)). They organize it by having a rotation they go through throughout the year, they have a qualifiers map pool that gets 32 teams out of x amount who registered. I believe the only requirements to be in a world cup is to have enough members (at least 3, I believe) and for them to be of reasonably high rank (preferring 5000 or lower, but I do believe they make exceptions where needed, but that is up for discussion).
