Software like LibreCAD and DraftSight offer functionalities similar to AutoCAD, albeit with a different user experience. These can be great alternatives for those on a tight budget.
There is no legitimate "portable" version authorized by Autodesk. Downloading cracked, portable, or otherwise unauthorized copies of AutoCAD from file-sharing sites, Google Drive links, or torrent platforms is: Autocad 2012 Portable Free Download 103 - Google
Searching for "AutoCAD 2012 Portable Free Download 103" typically leads to unofficial, high-risk websites. Autodesk, the developer of AutoCAD, does not offer a "portable" version of its software, nor does it provide free full downloads for retired products like the 2012 edition. Critical Risks & Reality Google Drive links