Gujarat High Court Criminal Manual (subordinate court practice), 1977
The question of the age of an accused person is frequently of importance in other cases also. Mercy petitions are often presented on the ground of youthfulness of the condemned prisoners. At the time of the examination of the accused the Judge or Magistrate should, therefore, specifically ask each accused person his or her age for the purpose of recording it. If the Judge or Magistrate suspects that the age stated by the accused, having regard to his or her general appearance or some other reason, has not been correctly stated, then the Judge or Magistrate should make a note of his estimate. The Court may also, when it so deems fit or proper, order a medical examination of the accused for the purpose of ascertaining his correct age. If any documentary evidence on the point of age is readily available, the prosecution may be asked to produce it. The Court in such cases also, should insist upon the production of a school certificate and extract from the birth register or birth certificate, if available.