(6)Any licence granted may, from time to time, be renewed at the discretion of the Executive Officer-(a)in the case of an annual licence, for further periods of one year at a time; and(b)in the case of a temporary licence for such either further periods as the Executive Officer may think fit, but not exceeding at a time period specified in Clause (a) or Clause (b) of Sub-rule (2) as the case may be.