I have a macBook pro mid 2012 what is the highest system I can run on this machine?

Yes. See the following from Identify your MacBook Pro model - Apple Support

MacBook Pro (13-inch, Mid 2012)

Model Identifier: MacBookPro9,2

Part Numbers: MD101xx/A, MD102xx/A

Newest compatible operating system: macOS Catalina 10.15.7

Also see: How to get old versions of macOS - Apple Support

Though I have not ben able to find....Model Identifier: MacBookPro9,2

Part Numbers: MD101xx/A, MD102xx/A.

Do "About this Mac..." and then click "System Report..." near the bottom of the resulting window:

to see the identifier (red arrow):

The model Identifier is all your need. Those "MD" numbers are order numbers that track things like the keyboard localization, options, etc.