CS6 and its programs will not run on any Mac with an operating system of Catalina or later. Apple has changed the OS in Catalina so that Macs will only run 64-bit programs, and CS6 and earlier are all 32-bit programs.
Which macOS do you have? This might not be possible given legacy LR6's advanced age.
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Nancy O'Shea, Adobe Product User & Community Professional Alt-Web Design & Publishing ~ Web : Print : Graphics : Media
If M1 chip and/or Apple's BS operating system that old program may not work even if you do find a download
Direct Download Links https://prodesigntools.com/tag/ddl MAY help -you MUST do what it says in Note: Very Important Instructions -https://prodesigntools.com/adobe-cc-2015-direct-download-links.html#download-instructions -the prodesign links go directly to Adobe's file server, so this process --will only work until Adobe completely removes the old version(s) from the server . IF/When you do have a download, be sure to copy it to AT LEAST one external device -since Adobe does sometimes remove old versions from the server -a usb flash drive or hard drive, or write to a DVD -plus a text file containing your serial number