Whenever I Singh with Apple ID is showing Apple ID not valid either not supported

Hello,

For help with that you need to contact Apple. Click here --> Choose your country or region - Official Apple Support Select your country, then a product. If you don't see one that handles your issue then keep experimenting with selections until you reach one that gets you a chat session or a telephone call and get the representative to redirect you.

or:

Contact Apple for support and service by telephone --> Contact Apple for support and service - Apple Support

If your Apple ID is (either) not valid or not supported, get support and assistance from Apple directly, see  -> 

Contact Apple for help with Apple ID account security

Contact Apple for support and service - Apple Support