(a) the Registrar, or agent or employee of the commission; and

 

    (b) any other person for or on account of or in respect of any act done or purported to be done by him under the order, direction or instruction of the Registrar, or agent or employee of the commission, if the act was done in good faith and in a reasonable belief that it was necessary for the purpose intended to be served by it and for the carrying into effect the provisions of this Act.