TPC isn't a CAD program, but you can easily create CAD deliverables plus use CAD files in your TPC surveys.
Using Existing CAD Files (4:51) - Open a CAD file in TPC Desktop 2016, explore layers and entities, then send selected entities over to the Drawing View
DWG Files
TPC imports and exports DWG files from the Drawing View.
TPC can import and export current versions of DWG files all the way back to older versions like R9 or 2000. So no matter what DWG file the client sends you, you can open it.
Civil3D CAD files an be opened in TPC, but you may not have access to all the data. However, you can access all the data through TPC's LandXML interface.
DGN Files
TPC imports and exports DGN files from the Drawing View.
DXF Files
TPC imports and exports DXF files from the Drawing View.
