can a I mac display be connected to I mac mini.

No, the iMac cannot be used as a monitor for the Mac mini.

Target display mode is a feature that was available only with certain older iMac models.

The feature has been deprecated by Apple and is no longer supported in hardware or software.

Only the following older iMac models can be used as an external display when plugged into another older Mac model:

• iMac models introduced in 2011, 2012, 2013, and mid 2014 using Thunderbolt or Thunderbolt 2 cable.
• 24-inch and 27-inch iMac models introduced in 2009 and 2010 using Mini DisplayPort cable.
• The intended target iMac must be running macOS 10.13 High Sierra or earlier; it does not work with macOS 10.14 Mojave or later, or with Boot Camp and Windows.
• Retina display iMacs won’t work as target displays.
• In all cases the source Mac that you're connecting FROM must have been introduced in 2019 or earlier and have macOS 10.15 Catalina or earlier installed.

However, you might consider a third-party solution, for example: Luna Display or Duet Display.

I cannot vouch for the stability or performance of these third party options.

Hello.

If you are referencing something emulating a Split View mode, then no. Your iMac 27" is a computer within itself.

Regards,

mdp1101.