Section 135(2) in The Delhi School Education Rules, 1973
(2)The parent or guardian shall state the exact date of birth of his child or ward in the application for admission, Added by [and the statement shall be supported by a certificate of birth issued by a local authority, or where it is not available, the statement shall be supported by an affidavit.] [The Delhi School Education (Amendment) Rules, 1990 (w.e.f. 23.2.1990).]