If a website is offering a "full crack" or "lifetime license" for a $5,000 piece of software for free, you are the product—not the customer. Your data, your designs, and your computer's security are at risk.
Some users search for "Tuka Cad free download forever" hoping for an open-source miracle. However, Tuka Cad is proprietary software developed by a private company. Tukatech invests millions annually in R&D, algorithms, and 3D simulation technology. Giving it away for free permanently would bankrupt the company.