Section 30(6)(c) in The Merchant Shipping (Prevention of Pollution by Oil from Ships) Rules, 2010
(c)oil tankers delivered on or before 1st June, 1982, as defined in sub-rule, (33) of rule 1A, operating with dedicated clean ballast tanks, which without modification are not capable of discharging ballast water from-dedicated clean ballast tanks above the waterline, may discharge this ballast below the waterline provided that the discharge of the ballast water is supervised in accordance with clause (c) of sub-rule (8) of rule 18;-