Rest restring Pascod

If you mean that you've forgotten the passcode to unlock your iPad : Forgot passcode for your iPhone, iPad, or iPod touch, or your device is disabled - Apple Support

If it's that you've forgotten the Settings > General > Restrictions passcode then was it on the iPad when you last backed up ? If not then you can restore to that backup and it should be removed. If it was on the iPad when you last backed up then the only way to remove it is to reset the iPad back to factory defaults (you may need to use recover mode ; see half-way down the above link) and you can then re-sync your content back to the iPad - you won't be able to restore to the backup as that will keep the code in place.