I am not sure this is possible unless there is something that gets published with DNN's release candidate versioning to make this possible or easy. But currently, when you have Release Candidates showing, you do not get any confirmation as to which version is being downloaded and installed.

In the image above, RC1 had been out for a few days, but RC2 had just dropped a few hours ago and in this case, appeared to have replaced RC1. I do note that the release Tag is /releases/tag/v9.11.1-rc2 so maybe there is a simple way to surface that info?