law: 6. Restrictions on imprisonment of offenders under twenty-one years of age.-
  (1) When any person under twenty-one years of age is found guilty of having committed an offence punishable with imprisonment (but not with imprisonment for life), the court by which the person is found guilty shall not sentence him to imprisonment unless it is satisfied that, having regard to the circumstances of the case including the nature of the offence and the character of the offender, it would not be desirable to deal with him under section 3 or section 4, and if the court passes any sentence of imprisonment on the offender, it shall record its reasons for doing so.
  (2) For the purpose of satisfying itself whether it would not be desirable to deal under section 3 or section 4 with an offender referred to in sub-section (1), the court shall call for a report from the probation officer and consider the report, if any, and any other information available to it relating to the character and physical and mental condition of the offender.