Section 117(b) in The Building And Other Construction Workers '(Regulation Of Employment And Conditions Of Service) Central Rules, 1998
(b)during the demolition of an exterior masonry wall or a roof from a point more than twelve metres above the adjoining ground level of such wall or roof, if persons below such wall or roof are exposed to falling objects, suitable and safe catch platforms shall be provided and maintained at a level not more than six metres below the working level except where an exterior built-up scaffold is provided for safe and adequate protection of such persons;
