What Do I Do If I Lost My iPad Passcode?
The first step is to connect your iPad or iPhone to the computer with which you last synced it. You can then restore your device from your last backup and reset the passcode.
If you haven't synced it to a computer or no longer have access to the computer where you synced it, you can sync it to a new computer. You will be forced to reformat the iPad and your data will no be present (a note: you will be able to redownload all your purchased apps from the App Store for free).