Section 155(b) in The Naval Ceremonial, Conditions Of Service And Miscellaneous Regulations, 1964
(b)from Lieutenant-Commander to Commander.(i)By Selection. - By selection from officers who have attained 2 years' seniority but not more than 8 years' seniority in the rank of Lieutenant-Commander. An officer should have served afloat for at least one year in the rank of Lieutenant-Commander or Acting Lieutenant-Commander.
