It takes 11 attempts to disable an iPad over the span of two and a half hours, please see the picture below.
Because it is an Apple security measure, the only way to fix a disabled iPad is to erase it and, hopefully, restore it from a backup. However, if you don't have a recent backup or any backup at all there could be significant data loss.
You can read more about the process here:
In the future, if you forget your iPad passcode, we can send a command to your iPad to clear the passcode that won't cause any data loss, as long as the iPad isn't disabled and on a network.