In the case of the public trust which is created by a will, the executor of such will shall within one month from the date on which the probate of the will is granted or within six months from the date the testator’s death whichever is earlier make an application for the registration in the manner provided in section 18 and the provisions of this Chapter shall mutatis mutandis apply to the registration of such trust:

Provided that the period prescribed herein for making an application for registration may, for sufficient cause, be extended by the Deputy or Assistant Charity Commissioner concerned.