Section 791(c) in Police Regulations, Bengal , 1943
(c)A probationer promoted from the rank of Assistant Sub-Inspector shall be trained in different branches of police work, generally on the lines indicated above, but the period of training shall be limited to one year only and the prescribed course shall be altered accordingly. The Deputy Inspector-General of the Range shall see that the probationer is specially trained in those branches of police work of which he has had least previous experience.