I'm the owner. Apple activation says it synced with "email@example.com" but my gmail starts at k and says it cannot be used to unlock. I checked icloud and ipad2 isnt sync and only has my other device. I have the receipt but it doesn't have the serial number in it. There is no apple store in my city. I bought the ipad from authorised seller, can they activate it?
No. An Apple Authorized Reseller (AAR) or Apple Premium Reseller (APR) cannot activate your iPad when it has an activation lock.
You could try to call Apple Care so they can help you with activating your account. Take a look at this website to find the Apple Care number for your country.