Real/VNC is a Commercial Remote Control Application, commonly used by
various hardware manufacturers to support their systems in the field. IBM
uses it extensively, and in such situations it can be legitimate. Only in
the case where the owner of the system is unaware of it's installation or
function should you be concerned, because it can also be used for
illegitimate purposes by malware.
If the owner of that system wants to keep VNC installed the correct action
would be to exclude it from scanning in the Windows Defender Tools/Options.
Otherwise, it should be un-installed or quarantined depending on how it got
on the system to begin with.