Section 84(1)(b) in Tamil Nadu State Housing Board Act, 1961
(b)that any person is in unauthorized occupation of any Board premises, the competent authority may, notwithstanding anything contained in any law for the time being in force, by notice served (i) by registered post, or (ii) by affixing a copy of it on the outer door or some other conspicuous part of such premises, or (iii) in such other manner as may be prescribed, order that the person authorised to occupy as well as any other person who may be in occupation of the whole or any part of the premises shall vacate them within one month of the date of the service of the notice.