Section 27(1)(b) in The Merchant Shipping (Prevention of Pollution by Oil from Ships) Rules, 2010
(b)At sea, the following criteria shall be applicable -(i)the area under the righting lever curve (GZ curve) shall be not less than 0.055 m.rad up to θ=30º angle of heel and not less than 0.09 m.rad up to θ 40º or other angle of flooding θf if this angle is less than 40º and additionally, the area under the righting lever curve (GZ curve) between the angles of heel of 30º and 40º or between 30º and θf if this angle is less than 40º shall be not less than 0.03 m.rad;