If you meant something else, please consider the following common possibilities:

Could you please clarify this file belongs to, or what you are trying to accomplish?

on Windows.

Because 6MS.7z looks like a compressed archive file (the .7z file extension is used by the free and open-source file archiver 7-Zip), it most likely refers to a specific local file on your computer.

In product catalogs, strings like 6MS/7Z are sometimes used to identify replacement parts for specific electronics (for example, switches in certain Dolce Gusto coffee machines).