My ipad is locked with 1-877-662-*** (Apple) to call for support? Is this a SCAM

That is a scam. Apple does not put a number on your device when locked.

Please see this: Recognize and avoid phishing messages, phony support calls, and other scams - Apple Support

If you forgot the passcode and its passcode locked, You'll need to restore it on a PC or Mac unless it gives you the option to reset it on the screen. Please see this: If you forgot your iPad passcode - Apple Support

Yes, its a scam. Apple will never contact you to inform you of an account or device lockout.

See >>> Recognize and avoid phishing messages, phony support calls, and other scams - Apple Support

Don’t respond to, or engage with, the message. Certainly do not, under any circumstances, attempt to contact anyone using the contact details that may have been provided.

Alerts of this nature are designed to scare the unwary into giving away sensitive information - or to fool you into doing something that you shouldn’t - usually to defraud you financially.

If you suspect that your AppleID has been compromised, follow the advice outlined here:

If you think your Apple ID has been compromised - Apple Support