And it will be 8x slowed down. He wants realtime playback.
You can drag your original clip into 24fps timeline (set fps interpolation to nearest). This should drop every 8th frame and you will end up with 24fps file which should play in realtime.
You still may end up with 2x slowed down playback (if Resolve doesn't understand file with 192fps and forces fps to 96fps- or if your source is image sequence). In this case it's messy to do with Resolve. Try 96fps for source and use 200% speed in timeline.
If you do want slowmo than don't change just playback fps but assign 24p for clip in Clip Attributes. This will be preserved on export. This is not what you said in first post though.