Lightroom6

Here you'll find the appropriate download links

Adobe Lightroom 6 (CC 2015) Direct Download Links – Free Trials | ProDesignTools

Scroll down to the section "Adobe Lightroom 6/CC 2015 Direct Download Links"

Save the installation file for further usage. It's not sure how long tihs files will be available.

Adobe are still offering a download of v6.14 here-

Lightroom 6 End of Support

When you buy a program via download you should always keep a copy on an external device

Direct Download Links https://prodesigntools.com/tag/ddl MAY help
-NOTE that you will have to search the site for your specific download
-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 external hard drive, or write to a DVD
-plus a text file containing your serial number if you have a serial number program