This extension allows you to import and visualize geotechnical data (such as borehole logs and soil strata) as dynamic Civil 3D objects.
: If the ".rar" file you mentioned is from an unofficial third-party source, be cautious of potential malware. It is always safest to download these "complementos" directly from the Autodesk App Store or your official Autodesk subscription account. Autodesk Civil 3d 2021 complemento.rar
If you are looking for general utility or regional standards, consider these official extensions available through the Autodesk Account Extensions Page : This extension allows you to import and visualize