Indra Sawhney v. Union of India (1992)

This nine-judge Constitution Bench judgment (decided November 16, 1992) is the foundational ruling on reservation policy in India.

Key holdings relevant here: - Total reservations in any cadre/grade cannot ordinarily exceed 50% of available posts. - Exceptions are possible only in "extraordinary situations" (e.g., remote/isolated regions with special circumstances). - "Creamy layer" must be excluded from OBC reservations (but this doctrine does not directly apply to SCs/STs). - Reservations in promotions for SCs/STs were held impermissible (subsequently overturned by constitutional amendments).