Okay so I know that nutrition is a big factor in the size of antlers, meaning the diameter of the tines and so forth. I am confused as to what determines the number of tines, with a buck with 6 points, 3 on each side, does that mean he is 3 years old?

No it does not. The size of the rack is dependent on age, nutrition and genetics. A year and a half old buck can easily be a six point buck, or even a small 8 point. Age will give mass to a rack and width and perhaps some more points but the age and number of points are not co dependent

Ditto to what OT said.