How do I import a .tp3 file into TBC? I tried to enter a new format in the file import editor but it doesn't want to read the file.
Can’t. TP3 is a Topcon proprietary format, not a public or Trimble format.
You can't directly but I believe you can make a free account/download from the link below to convert it into a file that is compatible with TBC
3D-Office | Topcon Positioning Systems, Inc.