which version of i movie is compaitable for macos high sierra 10.13.6

iMovie is only available from the AppStore. You can buy iMovie for free from the AppStore, but only the current version 10.1.14. It requires macOS 10.14.6 or later.

It you already own an older iMovie version from the App Store, you can try to download an older version by reinstalling from your Purchases history.

• Launch the AppStore and open the fourth tab "Purchased". You may need to sign in with your APpleID.
• Look for iMovie on the list of your Purchases. If you can see iMovie, try to download it from there.

Do you have, or have you ever had, a version of iMovie 10 on your Mac? If so, you can download the highest version that High Sierra can run (iMovie 10.1.12, I think), using this procedure:

To update/redownload iMovie 10, drag your iMovie 10 app from the Applications folder into the trash, but do not empty the trash. (You can skip that step if you had iMovie 10 on your computer before, but deleted it.) Sign in to the app

store and open your purchases folder by clicking on your name at the bottom of the app store side bar. You will see your purchases displayed, including iMovie 10. Redownload/update iMovie from there. If not successful, drag your present

iMovie app out of the trash (if you moved it there) and return it to the Applications folder.

If you never had acquired iMovie before, however, you will not be able to obtain an earlier version unless you can upgrade to Mojave or Catalina. Catalina is incompatible with 32bit apps, so if you have any 32bit apps on your Mac they wouldn't work with Catalina.

-- Rich