If you must open it, do so in a virtual machine or a "sandbox" environment to protect your main OS.
The file appears to be a specific compressed archive, likely associated with a specialized gaming utility or script . Based on the naming convention, "RCS" typically stands for Recoil Control System , a tool often used in first-person shooters (FPS) to automate weapon patterns.
Often contains .lua , .ahk (AutoHotkey), or .exe files to execute the control logic.
.rar files are a common vehicle for "stealers" (Trojan horses) that can grab your passwords or crypto wallet keys upon extraction.
Likely designed to minimize vertical and horizontal kick when firing weapons in games.