I am from India but it doesn't allow to edit Apple ID using Mobile number

👉 If you already have an Apple ID that's an email address, you might not be able to change it to a mobile phone number.

then it error as Enter a valid email address to use as your Apple ID.

Because your phone number is already use, it is linked to your Apple ID.

👉 get support from Apple directly -> Get Support or call Apple in your region see -> Contact Apple for support and service or check -> here for more support and assistance.

Can I create Apple ID with Phone number ?

Yes, but I wouldn't if I were you.

Your Apple ID is the personal account you use with all Apple products and services. It includes the email address and password you use to sign in, as well as the contact, payment, and security details that you use with Apple.

👉 You can’t merge multiple Apple ID accounts.

See the following Apple articles

Sign in with your Apple ID -> Sign in with your Apple ID - Apple Support

Manage and use your Apple ID -> Manage and use your Apple ID – Apple Support (UK)