To obtain a legal free copy, you must follow the official registration process on the page: Creo 6.0 Academic editions - PTC Community
PTC Creo 6, a standard for 3D CAD design, is available for free primarily through official educational programs or as lightweight "Express" versions. While newer versions like Creo 11 and 12 are currently promoted, students and educators can still access legacy versions like 6.0 for academic use.
: A free viewer for opening and visualizing 3D CAD models without needing a full license. How to Access the Free Download