The term seems to refer to a part of a larger file or series, likely a video, given the format (fc2ppv suggests a format or series identifier, 12617991 could be an identifier or code for the content, part6 indicates it's a segment of a larger work, and rar signifies it's been compressed into a .rar file). Repackaged files are often redistributed versions of original content, sometimes to make them more accessible or to bypass certain restrictions.
: This refers to "FC2 Adult Market," a popular Japanese video-on-demand platform where independent creators sell content. "PPV" stands for Pay-Per-View.