Hi Fidel, welcome to DUC.
AFAIK a current subscription or latest perpetual license covers all "recent" versions at least of 20xx.x versions, may even cover 12.6 and later. If your decision is being made by what version of macOS the mbox mini is compatible with then you can simply look that up here:
https://avid.secure.force.com/pkb/ar...tibility-Chart. Some legacy perpetual licenses also cover back to Pro Tools 10.
What exact Pro Tools licenses (perpetual or subscription) copy of Pro Tools do you own today? What versions are they for? Are you trying to be compatible with what licenses you own today?
I have no idea what your needs/motivations/budget are, and that changes any decision here. Personally I'd want to be on Big Sur (Monterey currently has issues with some plugins, and likely more) and the Pro Tools 2021.12 and would get there by buying another interface (the Focusrite 2i2 is the widely used entry point interface to look at... it's class compliant means it will work on all versions of macOS including on new Apple silicon Macs that the mbox family will not work on. But there is an incredible selection of nice interfaces from many vendors, some of which provide better support than Avid ever did... Avid wisely left the consumer interface market). Especially if you are going to spend hundreds of dollars annually on Pro Tools I'd be willing to spend that and more to get an interface that lets me use the latest stuff. I'd also want to be on a Pro Tools release that is within the last few years, including because core bugs in plugin processing were fixed during 2018 or so, and there have been some useful features added... whether they matter to you or not I have no idea.
Has this Mac been used for Pro Tools before with this interface? Does it meet recent systems requirements... especially does it have enough memory?... I'd want to see 16GB minimum with any 64 bit version of Pro Tools (11, 12, 20xx.x).
If you have more questions please tell us the exact model/date code name/EMC # of the Mac you own (e.g. EMC # is often printed on the mac). We don't need an essay on stuff, clear version info tells us all all we need to know, including min and max macOS version support.