Upgrading iOs on 2012 MacBook Pro

If your MacBook Pro is from Mid-2012 or later, it can be upgraded to macOS Mojave, which is the latest version of macOS. iOS is for iPhones and iPads, and the latest version of that is iOS 12.

To check when your Mac was built click on the Apple Logo in the menu bar and click "About this Mac". For more information, see macOS - How to Upgrade - Apple

You can check if your device is compatible with iOS 12 by going to iOS 12 is compatible with these devices - Apple Support

It can be upgraded to Mojave if that's what you mean.

iOS is for iPhones & iPads etc. Is that what you want?