With a Level 12 Rally Point it is possible to send out up to 200,000 troops per attack.
Please note that a Level 12 Rally Point will not allow you to send out more than 11 armies simultaneously.
To increase the number of Troops you can send out from the Level 12 Rally Point, utilize Aura items (such as the Aura of Command) to maximize the power of your marches!
This information can also be found in the building statistics by clicking on the Rally Point in your City.