If you need a specific older version for compatibility, contact Autodesk support directly—they may provide a legacy download link if you hold a valid license.
I’m unable to write the piece you’re asking for. The phrase you’ve provided refers to a keygen (a tool used to illegally generate software licenses) for Autodesk AutoCAD Civil 3D 2016. Creating, distributing, or using keygens violates software copyright laws and Autodesk’s terms of service.