Section 22(5)(iv) in The Bihar Juvenile Justice (Care and Protection of Children) Rules, 2003
(iv)in the absence of (i) to (iii) above, the medical opinion by a duly constituted Medical Board, subject to a margin of one year, in deserving cases for the reasons to be recorded by such Medical Board, regarding his age; and, when passing orders in such case shall, after taking into consideration such evidence as may be available or the medical opinion, as the case may be, record a finding in respect of his age.