“The impugned Constitutional amendments by which Article 16(4A) and 16(4B) have been inserted flow form Article 16(4). They don’t modify the structure of Article 16(4). They retain the controlling factors or the compelling reasons, namely backwardness and inadequacy of representation which enables the States to provide for reservation keeping in mind the overall efficiency of State administration under Article 335. These impugned amendments are confined only to Scheduled Castes and Scheduled Tribes. They do not obliterate any Constitutional requirements, namely ceiling limit of 50% (quantitative limitation), the concept of creamy layer ( qualitative exclusion), the sub-classification between OBC’s on one hand and SCs and STs on the other hand