Vtcs2.rar -

That's a very specific file name! To make sure I'm giving you the right steps, I need a little more information.

: Are you looking to create a specific design feature (like a toolpath or a shape) within a project file that was shared as a .rar? VTcS2.rar

: Is this a source code archive where you want to add a new functional feature to the program? That's a very specific file name

7-Zip / Feature Requests / #1198 Option to create RAR files? : Is this a source code archive where

The file could be related to a few different things, and the process for "creating a feature" depends on which one you mean:

: Does this involve adding a feature to how you manage or pack .rar files within a specific utility?

Could you clarify what kind of you are trying to create and what software you are using to open that .rar file?