Section 83A(6)(iv) in The Central Goods and Services Tax Rules, 2017
(iv)In case the goods and services tax practitioner having applied for appearing in the examination is prevented from availing one or more attempts due to unforeseen circumstances such as critical illness, accident or natural calamity, he may make a request in writing to the jurisdictional Commissioner for granting him one additional attempt to pass the examination, within thirty days of conduct of the said examination. NACIN may consider such requests on merits based on recommendations of the jurisdictional Commissioner.