Section 228(2) in Goa Succession, Special Notaries and Inventory Proceeding Act, 2012
(2)However, the disposition is valid even when the future heir or legatee is born beyond the period of 300 days from the date of the death of the testator, if the disposition is in favour of the children yet to be born who are descendants in the first degree of certain or specified persons alive at the time of the death of the testator.
