Section 125(1) in Delhi Prisons (Inspection, Meetings and Duties of Officers) Rules, 1988
(1)For a convict-watchman, that(a)he is a prisoner of the casual class, save in the case of jails reserved for habitual prisoners, where prisoners of the habitual class shall be eligible for appointment, provided that no habitual prisoner with more than 2 previous convictions shall be appointed as Night watchman in the habitual barracks.(b)his substantive term of imprisonment is not less than twelve months;(c)he has completed one-third of his substantive sentence;(d)he is well-behaved and an industrious prisoner;(e)he has at the time of his appointment earned at least three-fourths of the remission which it was possible for him to obtain; and that(f)he has not been convicted of cheating, administering poisonous drugs, unnatural offence, kidnapping or abduction for purposes of prostitution, or any other offence which, in the opinion of the Superintendent, would render it undesirable to appoint him to the office of convict officer.