The Supreme Court held that a claim of juvenility can be raised at any stage of criminal proceedings, including after conviction and final disposal of a case. In Mahavir @ Avnish v. State of Madhya Pradesh, the appellant claimed that he was below 18 years of age when the alleged offence was committed. The Court treated the question of juvenility as a jurisdictional issue rather than merely a procedural defence. It held that if a person was a child on the date of the offence, the ordinary criminal court could not exercise jurisdiction over that person in the same manner as an adult accused. The Court also examined the conviction under Section 201 IPC and found that the prosecution had failed to establish the underlying offence sufficiently. Consequently, the conviction could not independently survive. The judgment emphasises the protective purpose of the Juvenile Justice framework and confirms that procedural finality cannot defeat a genuine claim of juvenility. It is important for understanding Section 7A of the Juvenile Justice Act, age determination and jurisdiction concerning children in conflict with law.