Proof of consent of the Authority, City Corporation authorities or the officers

Whenever under this Act or any rule, bye-law or regulation made under it, the doing of or omitting to do anything or the validity of anything depends upon the approval, sanction, consent, concurrence, declaration, opinion or satisfaction of,-

1. (a) the City Corporation, a Standing Committee or the Chief Commissioner of the Authority or the Commissioner of the City Corporation; or
2. (b) any City Corporation officer, A written document signed in the case of (a), by the Chief Commissioner or the Commissioner and in the case of (b) by the said officer, purporting to convey or set forth such approval, sanction, consent, concurrence, declaration, opinion or satisfaction, shall be sufficient evidence thereof.