What is the average weight of a 6' man?

Weight is not as important as BMI. Many charts will claim to know your BMI just by looking up your weight but they're wrong. Lean Body Mass is the most important number.

For example, charts may say that someone should weigh about 180, but by checking his BMI he might find that his lean body mass is 214.

If you're serious about exercise and physical condition you need to have your BMI calculated and you don't get it from stepping on a scale. Many sports physicians and physical therapists have the apparatus to PROPERLY test your BMI.