tow capacity
Advice? Don't tow that trailer with that truck

. Without putting ANYTHING in the trailer, no water, no waste, no propane, no food, no clothes, no hoses to hook up with, etc, you are already overloaded. 6000 pounds is a conservative, marketing value, and represents what you can theoretically tow with a stripped truck, no cargo, no accessories, little fuel and no people other than a 150 pound driver. Dry weight is with NOTHING added to the trailer, and often does not include some of the options installed.
So, the 6200 is probably low and the 6000 probably high, which means in a real world situation you will be way over the safe limit.
If you must tow it, make sure your truck has a top of the line transmission cooler and a transmission temperature guage. Monitor your transmission temp like a hawk! Don't take anything with you which is not absolutely essential (no water in tank, dump before moving, minimal propane, bare minimum personal stuff, minimal food, etc). Strip off all truck accessories which are not essential. Check into upgrading the truck tires to a higher load rating tire. Add rear suspension capability, probably a high capacity air spring would be the most practical. Go slow, and avoid hills like the plague.