Section 160(4) in The West Bengal Motor Vehicles Rules, 1989
(4)When a permit or a part of a permit has become dirty, torn or otherwise defaced so as. in the opinion of the Regional Transport Authority or the State Transport Authority, to be illegible, the holder thereof shall surrender the permit or part of the permit, as the case may be, to the Transport Authority and apply for the issue of duplicate permit to it or part of a permit in accordance with the rule.
