93 maybe the manufacture year
From another source:
Rossi Model 68 Champion II
Notes: The first revolver of this series, the Model 68, was a development of an earlier revolver (the Model 27 Pioneer), and was basically the Pioneer with an adjustable rear sight and a ramp front sight. It had a barrel slightly under 3 inches, and was available only in .38 Special. It was produced from 1978-85. The Model 68S is a modernized version of the Model 68; it has a 2 or 3-inch barrel, a shrouded ejector rod. Blued or nickel-plated finish, and walnut grips. It began production in 1993 and remains in production. The Model 69 is basically a version of the Model 68 in .32 caliber. The Model 70 is the same idea, but is chambered for .22 caliber.
http://www.pmulcahy.com/revolvers/brazilian_revolvers-rossi.htm
I know yours doesn't have the number 68 anywhere on it, but this the closest match I could find . Good luck!