Cellular connection failed

Thanks for visiting the Apple Support Communities srihari161,

If you are having trouble setting up your Apple Watch with cellular data, we would suggest first making sure you are following the how-to set up cellular steps in the Apple Support article Set up cellular on Apple Watch - Apple Support.

Once you've confirmed those steps, we would recommend trying the following troubleshooting to see if you can get your cellular set up:

1. Restart your iPhone: Restart your iPhone - Apple Support and your watch: Restart your Apple Watch - Apple Support. This step by itself can often resolve a variety of unexpected behaviors.
2. Make sure your iPhone 12 mini is up-to-date with iOS 16.3: Update your iPhone or iPad - Apple Support. Having the latest updates ensures all software on your iPhone ensures your watch also has access to any necessary software and updates.
3. Unpair your watch: Unpair and erase your Apple Watch - Apple Support and set it up again: Set up your Apple Watch - Apple Support. This will help us isolate the issue a bit further, and clear out any issues that might have occurred during initial pairing.

If you still need help after that, please get in touch with Apple Support directly. They will have access to additional tools and resources to further investigate what could be occurring. You can reach them here: Get Support.

Have a great day.