(1) Every notice, order or direction issued under this Act shall, save as otherwise expressly provided in this Act, be served,-
(a) by giving or tendering the notice, order or direction [or] by sending it by registered post to the person for whom it is intended; or
(b) if such person cannot be found, by affixing the notice, order or direction on some conspicuous part of his last known place of abode or business, or by giving or tendering the notice, order or direction to some adult member or adult servant of his family or by causing it to be affixed on some conspicuous part of the building or land, if any, to which it relates.
(2) Where the person on whom a notice, order or direction is to be served is a minor, service upon his guardian or upon any adult member or adult servant of his family shall be deemed to be the service upon the minor.
(3) Every notice, order or direction, which by or under this Act is to be served as a public notice, order or direction or as a notice, order or direction which is not required to be served on any individual therein specified shall, save as otherwise expressly provided, be deemed to be sufficiently served if a copy thereof is affixed in such conspicuous part of the office of the Competent Authority or in such other public place during such period, or is published in such local newspaper or in such other manner, as the Competent Authority may direct.