Section 50(5) in The Central Motor Vehicles Rules, 1989
(5)In case of agricultural tractors, the registration mark need not be inclined to the [vertical plane by more than 45 degrees] [Substituted by GSR 111(E), dated 10.2.2004, for 'vertical by more than 30 degrees'(w.e.f. 10.8.2004).].
