Section 77(1A)(a) in The Employees' State Insurance Act, 1948
(a)the cause of action in respect of a claim for benefit shall not be deemed to arise unless the insured person or in the case of dependants benefit, the dependants of the insured person claims or claim that benefit in accordance with the regulations made in that behalf within a period twelve months after the claim became due or within such further period as the Employees Insurance Court may allow on grounds which appear to it to be reasonable;