hello because of multiple wrong password my iPad shows unavailable.

There is an Apple article that explains what to do if you have forgotten an iPhone or iPad passcode. Click on the following link: If you see an iPhone or iPad unavailable message or Security Lockout screen - Apple Support

If that is not an option, you will need to use a computer. See: If you forgot your iPhone passcode - Apple Support

Yes because apple will think someone that is not the owner is trying to log in on your Ipad so it will say 1 min then 2 min then 4 min etc