iMac 2013
Can someone advise me if the Mac Mini can be used on my 2013 27" iMac.
Thanks
iMac 27″, macOS 10.15
if you mean as display using target display then only if the mac mini is also rather old
target display really is a thing of the past Use your iMac as a display with target display mode - Apple Support
but good news is a real computer monitor would use a fraction of the power of that a 27" imac running does