This is the mumbo I got on the side of my 00 Ram 1500 4×4

All I really understand out of that is that R16 is the size of my actual tire correct? So I have 16in Tires?

Could anyone explain this to me?

And also .. what size tire/rim would you recommend on this type of truck? (I am looking into Mickey Thompson Wheels)

I have/am building a Hydrogen cell with a relative of mine which completely takes out the need for gas in my truck anyways .. so fuel mileage isnt really a problem.