A 6.24 MB ZIP archive named only UC6, which tells nothing certain about the device, board number or contents. The code could be a project or model abbreviation, but it cannot be identified from the name alone. Extract the archive and check the file types and any title pages or embedded strings to see what it covers. Before using a schematic, boardview or firmware image from it, confirm that the board number and revision match the hardware on your bench.
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 @vinafix_bios. Enginerys does not host this file.
How to open a .zip file
Compressed archive that every operating system opens without extra software.
Built-in OS tools7-Zip