A file named is typically a compressed archive containing Virtual Studio Technology (VST) audio plugins. Because .rar is an archive format, it is not the plugin itself but a container used to group and compress files like installers or plugin components. How to use a VST.rar file
Move these manually into your Digital Audio Workstation's (DAW) designated plugin folder. VST.rar
Tools like 7-Zip or PeaZip are free, open-source options for Windows and Linux. A file named is typically a compressed archive