Section 76A(4) in West Bengal Industrial Disputes Rules, 1958
(4)Where permission to lay-off has been granted by the said authority, the employer concerned shall give to the Secretary to the Government of West Bengal, Labour Department, Labour Commissioner, West Bengal and the Conciliation Officer concerned, notice of commencement of such lay-off in Form "O" ; and where permission to continue a lay-off has been granted by the said authority the employer shall give to the Secretary to the Government of West Bengal, Labour Department, Labour Commissioner, West Bengal and the Conciliation officer concerned, a notice of such lay-off in Form "O".