Unable to open .cdr file from DVD on Mac

• CDR files can belong to e.g. Disk Utility (or its helper app DiskImageMounter) by Apple. These would typically be disk images, much like .dmg and .iso: a file representing a volume or disk. For many formats (but not all), these can be mountable in Finder. Apple Disk Utility would use .cdr for the “DVD/CD Master” format, a special format for copying DVDs or CDs, although it can also be used for imaging folders. This file type should have better interoperability with third party apps than e.g. .dmg.
• CDR files can belong to CorelDRAW by Corel. These would typically be vector drawings, not disk images.

1. If you do a control-click (or right-click) on the .cdr file in Finder, then a contextual menu should pop up, allowing several options, including “Open with…”. Verify that DiskImageMounter is listed as the default app for opening this file type. Else choose DiskImageMounter anyway.
2. Or: You can launch Disk Utility and mount a disk image from within the app: Menu File﹥Open Disk Image…﹥
3. Also check the file size. Is it as large as you expect? Zero kB or a few kB isn’t enough for meaningful data; then something may have gone wrong in creating or copying.

That file is a CorelDraw file and you don't have the software to open it. A quick AI internet search for the following;

To open a .cdr (CorelDRAW) file without Corel software, use free, third-party alternatives like Inkscape (direct editing) or LibreOffice Draw. For quick viewing or conversion use specialized viewers such as CDR Viewer 4 (Mac)

Yes, Inkscape can open Corel Draw (cdr) files, primarily versions 7 through X4, and possible later versions of this application. If the cdr content is in CMYK color model, Inkscape may open it in RGB with different color appearance. Inkscape is not a panacea and your mileage with Corel Draw images may vary.

Inkscape offers Apple Silicon and Intel versions. Get the first for your iMac 24.