Mac mini 2023: What Version HDMI and DisplayPort is used?

Apple doesn’t specify, use the spec to figure out which M2 you need for your monitor(s) Mac mini - Technical Specifications - Apple

The Mac mini can use most any display, with the right connection.

see > Connect a display to Mac mini - Apple Support

If you are having an issues with a display or connection to that display?

Then please tell us the brand and model of the display.