Section 15(4)(d) in Tamil Nadu Recognised Private Schools (Regulation) Rules, 1974
(d)Appointment to the post of Headmaster of Higher Secondary School shall be made by the method specified in clause (ii) either from the category of Headmasters of High Schools or Teachers' Training Institutes or from the category of Post-Graduate Assistants in academic subjects or Post-Graduate Assistants in Languages provided they possess the prescribed qualifications.]