Could use some more info.
What version itunes are you using? (update to latest version)
Are trying to sync via a mac or pc? (what version OS is on pc)
When you connect ipad to computer, then open itunes what happens? Do do see the pop-up message that reads: 'itunes has detected an ipad in recovery mode.....?
If You Are Locked Out Or Have Forgotten Your Passcode
iOS- Understanding Passcodes
If you have forgotten the restrictions passcode