(1) Nothing in section 24 shall be deemed to prohibit,--
(a) the exercise, in accordance with the rules, if any, made under section 14, of any right continued under that section; or
(b) the exercise of any right created by grant or contract in the manner described in section 20; or
(c) any act done with the permission in writing of a Forest Officer duly empowered to grant such permission, or under any rule made by the State Government.