Where any accused person, having been found by reason of unsoundness of mind to be incapable of making his defence, is in custody or under detention under section 121, any officer prescribed in this behalf, may,--
(a) if such person is in custody under sub-section (4) of section 121, on the report of a medical officer that he is capable of making his defence, or
(b) if such person is detained in a jail under sub-section (5) of section 121 on a certificate of the Inspector-General of Prisons, and if such person is detained in a lunatic asylum under the said subsection, on a certificate of any two or more of the visitors of such asylum and if he is detained in any other place under that sub-section, on a certificate of the prescribed authority, that he is capable of making his defence,
take steps to have such person tried by the same or another Assam Rifles Court for the offence with which he was originally charged or, if the offence is a civil offence, by a criminal court.