RAR archive labelled with the Quanta board code GM6C, most likely holding a schematic or related service documentation for a laptop mainboard built by Quanta. The name does not state the laptop brand, model or revision, so the contents should be opened and checked before use. Quanta uses short two- or three-letter project codes, and the code silk-screened on the PCB, together with its revision, must match before you trace power rails, check signal paths or locate test points. The archive is about 1.06 MB and opens with WinRAR or 7-Zip.
The button opens the matching file on RM Schematics, or a source page if it is not catalogued there yet. The original attachment is from @IT_SERVICE_WORLD. Enginerys does not host this file.
How to open a .rar file
Compressed archive — the usual wrapper for a schematic + boardview pair or a BIOS + EC set.