law: 10. Filling of vacancies in office of Trustees.-
  (1) In the case of a vacancy in the office of a Trustee appointed by name or an elective Trustee caused by the expiration of the term of office of such Trustee, the appointment to fill such vacancy shall be made or an election to fill such vacancy shall be completed, as the case may be, within two months immediately preceding the date of expiration of such term.
  (2) In the case of a vacancy in the office of a Trustee appointed by the Central Government by virtue of an office, the appointment to fill such vacancy shall be made within one month of the occurrence of such vacancy.
  (3) In the case of a casual vacancy in the office of a Trustee appointed by name or an elective Trustee caused by the death of such Trustee or by virtue of the provisions of section 8, such vacancy shall be filled within one month of the occurrence thereof by appointment or election, as the case may be, in the manner hereinbefore specified:
  Provided that the Trustee so appointed or elected shall retain his office so long only as the vacating Trustee shall have retained the same if such vacancy had not occurred:
  Provided further that no such casual vacancy occurring within three months of the date of expiry of the normal term of office of the vacating Trustee shall be filled up under this sub-section.