De register my mobile number from deleted Apple id

Hello JASBIR442,

We want to get clarification on the steps you took to 'delete' this Apple ID.

Did you deactivate or permanently delete this Apple ID? If you deactivated the Apple ID, you can enable the account again to make changes, like removing your associated phone number: How to deactivate your Apple ID account - Apple Support

However, if you permanently deleted the Apple ID, there isn't much you can do. All account information would have been removed from Apple's servers, so you wouldn't be able to remove the associated phone number: How to delete your Apple ID account - Apple Support

Learn more about these self-service tools here: Understand and control the personal information that you store with Apple - Apple Support

Hoping to hear back, take care.

Hey there JASBIR442, 

To change or add another trusted phone number, you'll need to follow Two-factor authentication for Apple ID   

Manage your trusted phone numbers

To use two-factor authentication, you need at least one trusted phone number on file where you can receive verification codes. Consider verifying an additional trusted phone number other than your own phone number. If your iPhone is your only trusted device and it is missing or damaged, you will be unable to receive verification codes required to access your account.

Update your trusted phone number on your Apple ID account page

1. Go to appleid.apple.com.

2. Sign in with your Apple ID.

3. Go to the Security section and click Edit.

If you want to add a phone number, click Add a Trusted Phone Number and enter the phone number. Choose to verify the number with a text message or automated phone call, and click Continue. To remove a trusted phone number, click  next to the phone number you want to remove.

Update your trusted phone number through account recovery

1. Go to appleid.apple.com.

2. Sign in with your Apple ID.

3. Select “Didn’t get a verification code?”, then select More Options.

4. You'll be redirected to iforgot.apple.com. 

5. Complete your account recovery request. Learn more about account recovery.

Have a good one!