Every 5 minutes, the map updates. Your clan gets 100 Reinforcements per tick, same as every other clan, no matter the size.
Voting
You get 5 votes. Tap tiles to place them:
Everyone in your clan votes. All votes are counted, and the clan's 100 Reinforcements are split proportionally across the tiles that got votes. More votes on a tile means a bigger share.
Hit Confirm Votes to lock in. You don't have to use all 5.
Attacking
Territory
If your clan has no tiles, pick any spot on the map to drop in. Your votes must form a connected cluster.
At the end of the day, the map freezes. Whatever it looks like stays forever.