This naming convention is frequently seen in community-made mods, such as the Ultimate NBA 2K12 Mod Pack , which is often distributed in several download parts.
To successfully use this file, you must have all parts of the archive (część1, część2, etc.) saved in the same folder. You only need to right-click the first part ( część1.rar ) and select "Extract" using a program like WinRAR or 7-Zip to rebuild the full game or mod files.
The text "NBA2K12.część1.rar" refers to the first part of a multi-volume compressed archive for the video game .
"Część" is the Polish word for "Part." So, the filename translates to "NBA2K12.part1.rar" .