225 is the width in millimetres of the tyres cross section.
60 is the Aspect Ratio, it is the ratio of the sidewall height to the cross section width.
R17 Radial construction. R stands for radial-ply construction.
97Y inches, stands for the diameter of the wheel that the tyre is designed to fit.
is the load index i.e. the maximum weight each tyre can carry at full speed.
is the speed rating i.e. the maximum speed for the tyre at full load.