Section 95(5)(d) in Delhi Motor Vehicles Rules, 1993
(d)[ In the case of educational institution buses and medium or heavy passenger motor vehicles being used for the purpose of transporting school students, horizontal window steel bars shall be fixed on the exterior of the bus in such a manner that the distance between any two bars does not exceed twenty centimeters. [Inserted vide notification no. F 21/SECY/STA/97/PF/365 dated 22-06-1998.]