What version of the OS are you trying to download to this particular Mac mini? High Sierra is the latest version 2011 mini's can take.
So I'm not trying to upgrade the Mac mini. it can stay at on High Sierra. I'm trying to upgrade our other Macs in our environment(Mac minis, MacBook pros, Mac Pros, iMacs) to Catalina, which I know are compatible with the aforementioned Mac mini(not sure if possible since I can't even download it from the App Store). sorry for the wonky explanation.
I'm trying to upgrade our other Macs in our environment(Mac minis, MacBook pros, Mac Pros, iMacs) to Catalina, which I know are compatible with the aforementioned Mac mini
It took me a bit of re-reading your post to understand what you meant by this, but I think I get it now. You're using the 2011 Mac mini as an "IT" machine of sorts to download the installer for Catalina, to upgrade the other Macs. Is that correct? If so, then I would recommend looking at this utility (http://dosdude1.com/catalina/), which will let you download Catalina on unsupported machines. Make sure to only use the download option and not download and patch.
Once you have it, you should be able to package it up or upload it etc. as needed to your Jamf environment.