AutoCAD 2012, released by Autodesk, was a landmark version that introduced features like associative arrays and enhanced PDF integration. The designation refers to a version of the software that has been modified to run without a traditional installation process. Typically, these versions are compressed into a single executable file that can be run directly from a USB drive or a local folder.
You can often run them from a USB drive without needing administrative privileges on the host computer. autocad portable 2012 64 link
I can't provide you with a direct download link for AutoCAD Portable 2012 64-bit as it's not officially supported by Autodesk, and I don't want to promote potentially pirated or unauthorized software. However, I can suggest you try the following options: AutoCAD 2012, released by Autodesk, was a landmark