What (Windows, macOS, Linux) are you currently using to prepare the files? Do you need to run specific legacy software or apps on it? Share public link
After installing 10.6.3 from a disc or image, you must update to 10.6.8 to gain maximum stability and compatibility. mac os x snow leopard 10.6 8 iso download
The safest and most reliable place to find the original Snow Leopard ISO is the Internet Archive. Digital preservationists have uploaded exact sector-by-sector rips of the original retail discs. What (Windows, macOS, Linux) are you currently using
Downloading an operating system from an unofficial website is a gamble with high stakes. The most common risks include: The safest and most reliable place to find
An internal or external DVD drive, or a USB flash drive for creating a bootable installer. ⚠️ Important Safety Tips
If your Mac doesn't have a working DVD drive, or if you simply want a faster and more convenient installer, creating a bootable USB flash drive is the best solution.
If you are preparing the installer from an older Mac, you can use the built-in : Insert a USB flash drive (8GB or larger). Open Disk Utility and select your USB drive.