Section 12(4) in The Juvenile Justice (Care And Protection Of Children) Rules, 2007
(4)If the age of a juvenile or child or the juvenile in conflict with law is found to be below 18 years on the date of offence, on the basis of any of the conclusive proof specified in sub-rule (3), the Court or the Board or, as the case may be, the Committee shall in writing pass an order stating the age and declaring the status of juvenility or otherwise, for the purpose of the Act and these rules and a copy of the order shall be given to such juvenile or the person concerned.
