Section 4(6)(c) in The Environment (Protection) Rules, 1986
(c)in any other case, if the document is addressed to the person to be served and-(i)is given or tendered to him; or(ii)if such person cannot be found, is affixed on some conspicuous part of his last known place of residence or business or is given or tendered to some adult member of his family or is affixed on some conspicuous part of the land or building, if any, to which it relates; or(iii)is sent by registered post to that person.