I.R. Coelho v. State of Tamil Nadu is a landmark judgment of the Supreme Court of India that was delivered in 2007. The case arose out of a challenge to the Constitution (Ninety-third Amendment) Act, 2005, which amended the Constitution to provide for reservation of seats for the economically weaker sections of the society in educational institutions, including private unaided institutions. The appellants, I.R. Coelho and others, challenged the validity of the Ninety-third Amendment on the grounds that it violated the basic structure of the Constitution.

The Supreme Court, in its judgment, upheld the challenge and declared the Ninety-third Amendment to be constitutional, but subject to certain limitations. The Court observed that the right to education is a fundamental right under Article 21 of the Constitution and is an essential part of the right to life. The Court also held that the right to education includes the right to establish and administer educational institutions, subject to reasonable regulation by the state.

The Court further held that the Ninety-third Amendment does not violate the basic structure of the Constitution, as it seeks to promote the right to education and the principle of equality of opportunity. However, the Court also held that the reservation of seats for the economically weaker sections cannot be applied in a blanket manner and must be subject to the “creamy layer” principle, which excludes the well-off members of the reserved categories from the benefits of reservation.

The judgment of the Supreme Court in the I.R. Coelho case was a significant development in the Indian constitutional law, as it upheld the Doctrine of Basic Structure and reaffirmed the primacy of the fundamental rights over the Directive Principles of State Policy. The Doctrine of Basic Structure is a judicial doctrine that limits the power of the Parliament to amend the Constitution of India and is based on the theory that the Constitution is not a mere legal document, but a social contract between the people of India and the government. It protects the essential features and fundamental principles of the Constitution from being amended by the Parliament.