Section 29B(2)(a) in The West Bengal Premises Tenancy Act, 1956.
(a)where the landlord has retired, or will retire within a period of less than one year, as a member of the naval, military or air force of the Union of India, a certificate by the Area or Sub-Area Commander within whose jurisdiction the premises are situated or by the Head of his Service or by his Commanding Officer that he has retired, or will retire, as such member and that he requires the premises for his own occupation and for the occupation of his family after retirement, or