Conversion from FreeCAD to PRC is not supported yet :(

FreeCAD is a customizable, open-source paramentic 3D CAD and BIM software with FEM support, built on the Opencascade geometric kernel. It was created primarily for product design and mechanical engineering, but it can be used in a wide range of industries, such as electrical engineering, or architecture. It runs on Windows, Mac OS, and Linux.

FreeCAD is made to craft real-life objects of different sizes and is perfect for a home user/amateur, programmer, experienced CAD software user, or educator. This software provides tools similar to those of SolidWorks, Catia or Autodesk Revit.

PRC (Product Representation Compact) is a 3D file format that can be used to embed 3D data in a PDF file.

This highly compressed format facilitates the storage of different representations of a 3D model. For example, you can save only a visual representation that consists of polygons (a tessellation), or you can save the model's exact geometry (B-rep data). Varying levels of compression can be applied to the 3D CAD data when it is converted to the PRC format using Adobe Acrobat 3D.