Section 77(10)(i) in West Bengal Municipal (Employees' Service) Rules, 2010
(i)No permanent teaching or non-teaching employee shall be granted leave of any kind for a continuous period exceeding five (5) years. When such an employee does not resume his duty after remaining on leave for a continuous period of five (5) years, or where such an employee after the expiry of his leave remains absent from duty. otherwise on ground of suspension for any period. which together with the period granted to him exceeds five (5) years, he shall unless the Board on reference from the School authorities and in view of exceptional circumstances of the case otherwise determines, be deemed to have resigned and shall accordingly cease to be in the employment of the School.