The maximum level of troops that can be donated varies by Town Hall level and Clan Level. See the max level that can be donated below:
To view the levels for your village, switch to the "Your Village" tab above.
You aren't logged in. If you have a Clash Ninja account, login to select your village:
Press the "Load" button above to fetch your village details.
Icons: = Locked but available at this TH level = Max level for this TH level = Can donate max level -1 = Levels below max level
You need to be logged into your Clash Ninja account to do this: