Recover data from locked iPad
This is a tough question even for law enforcement. There's some software out there that claims to do this, try Google. You can also jailbreak older devices but you don't say what kind of iPad you have.

http://www.redsn0w.us/2010/03/download-direct-links-jailbreak-guides.html

Try recovery mode if you don't have iTunes, at least you can use the iPad after.

http://support.apple.com/en-us/HT1212