The file extension .rar indicates the use of the Roshal Archive format. Unlike the more ubiquitous .zip , RAR is favored in high-volume distribution circles for its superior compression ratios and robust error recovery records. The inclusion of main suggests this is the primary archive, potentially accompanied by supplementary files like .nfo (info) or .sfv (verification) files in the original distribution.
"REFIX" generally implies that a previous fix was unsuccessful or incomplete. Consider the following scenario: NGG-V3--REFIX--main.rar