Explanation:

1992 Indra Sawhney & Others v. Union of India judgment laid down the limits of the state's powers: it upheld the ceiling of 50 per cent quotas, emphasized the concept of "social backwardness", and prescribed 11 indicators to ascertain backwardness. The nine-Judge Bench judgement also established the concept of qualitative exclusion, such as "creamy layer".^[10][11][12] The creamy layer is only applicable in the case of Other Backward Castes and not applicable on other group like SC or ST. The creamy layer criteria was introduced at Rs 100,000 in 1993, and revised to Rs 250,000 in 2004, Rs 450,000 in 2008 and Rs 600,000 in 2013.