How can I unlock my disabled iPhone 6?

Please view this following article:

If you forgot your iPhone passcode or your iPhone is disabled - Apple Support

Note that if you reset and erase the phone, you will lose all data that was stored only on the phone itself. E.g., if you have photos that were not synchronized to iCloud, and you have no backups of the phone, and you did not copy the photos off the phone in any other way, they are gone.