All rattlesnakes I have seen have black rings on the tail end just above the rattler do these show the age or something of a rattlesnake?

There are four species of rattlesnake with the black and white bands on the tail - the eastern diamondback, the western diamondback, the red diamondback and the Mojave rattlesnake. The bands indicate nothing about the age of the snake. They have the same number of bands as adults that they had when newborn.