Section 158(3) in The Delhi School Education Rules, 1973
(3)Up to a limit of twenty per cent of the total number of students on the rolls of the school in All the classes in the [Secondary or Senior Secondary stage] [Substituted by the Delhi School Education (Amendment) Rules, 1990 (w.e.f. 23.2.1990).] is on the 7th day of May of the year may be exempted from the payment of the whole or one half of the fees, and where any student in admitted after the 7th day of May but before the 31st day of August of that year, up to a limit of twenty per cent of the students so admitted may be exempted from the payment of the whole or one half of the fees.