Section 3(1)(d) in Tamil Nadu Recognised Private Schools (Regulation) Rules, 1974
(d)[ (i) High Schools. - The High Schools shall consist of Standards I to X, or VI to X or IX to X; [Clause d(i) and (ii) were substituted by G.O. Ms. No. 1502, Education, dated the 23rd September 1988.](ii)Higher Secondary Schools. -The Higher Secondary Schools shall consist of Standards I to XII, VI to XII, or IX to XII.]