As defined in section 5(11) `tenant ' means any person by whom or on whose account rent is payable for any premises and includes (a) such sub tenants and other persons as have derived title under a tenant before the 1st day of February, 1973; (aa) any person to whom interest in premises has been assigned or transferred as permitted or deemed to be permitted, under section 15; (b) any person remaining, after the determination of the lease, in possession, with or without the assent of the landlord, of the premises leased to such person or his predecessor who has derived title before the 1st day of February, 1973; (bb) such licensees as are deemed to be tenants for the purpose of this Act by section 15A; (c) xxx xxx xxx xxx xxx xxx" Thus the above sub section (bb) read with section 15A of the Rent Act makes the `tenant ' one of status and not of contract.