National Environment Appellate Authority Act, 1997
6. Vice-Chairperson to act as Chairperson or to discharge his function in certain circumstances-
(1) In the event of the occurrence of any vacancy in the office of the Chairperson by reason of his death, resignation or otherwise, the Vice-Chairperson shall act as the Chairperson until the date on which a new Chairperson appointed in accordance with the provisions of this Act to fill such vacancy enters upon his office.
(2) When the Chairperson is unable to discharge his functions owing to absence, illness or any other cause, the Vice-Chairperson or, as the case may be, such one of the Member as the Central Government may, by notification, authorize in this behalf, shall discharge the functions of the Chairperson until the date on which the Chairperson resumes his duties.