4. In proceedings before the Tribunal, a question shall only be admissible as evidence in pursuance of Article 44(2)(a) of the Order—
(a)where it was served before an originating application had been presented to the Tribunal, if it was so served before the end of the period of three months beginning with the day on which the person aggrieved first had knowledge or might reasonably be expected first to have had knowledge, of the act complained of, or before the end of the period of six months beginning with the day on which the act was done, whichever is the earlier;
(b)where it was served when an originating application had been presented to the Tribunal, either if it was so served within the period of twenty-one days beginning with the day on which the originating application was presented or if it was so served later with leave given, and within a period specified, by a direction of the Tribunal.