Yes, you can install Kali Linux on a laptop and sell it as a complete package. Kali Linux is a free and open-source operating system, and there are no restrictions on installing it on hardware and selling it. However, it's important to note that Kali Linux is a specialized operating system designed for security testing and ethical hacking. It may not be suitable for everyone's needs, and it's important to provide clear information about the OS and its intended use to potential buyers. Additionally, it's always a good idea to consult with a legal expert to ensure that your business practices are compliant with relevant laws and regulations.