The victim girl, who had recently taken admission in Class XI in the school, was allegedly ragged and stripped by the five students on July 8 inside a bathroom, ACP Swati Sharma said.
"In the absence of a law against ragging in schools, we have decided to register a case against the accused girls and the school administration under POCSO Act," Police Commissioner Ashok Rathore said.
The anti-ragging law applies to college students which is not the case here, he added.
The Secretary of the school said an internal committee has been set up to probe the incident and the accused girls have been suspended.