If it rained 6 inches of rain, how many inches of snow would that equal to?

Q: "Is it true that there is one inch of water in every ten inches of snow that falls?"

A: "The water content of snow is more variable than most people realize. While many snows that fall at temperatures close to 0 degrees Celsius (32 degrees Fahrenheit) and snows accompanied by strong winds do contain approximately one inch of water per ten inches of snowfall, the ratio is not generally accurate. Ten inches of fresh snow can contain as little as 0.10 inches of water and as much as 4 inches of water, depending on crystal structure, wind speed, temperature, and other factors. The majority of U.S. snows fall with a water-to-snow ratio of between 0.04 and 0.10."

https://www.nssl.noaa.gov/education/svrwx101/winter/faq/