The highest constitutional court in India is the Supreme Court.

The Supreme Court of India is the apex judicial body in the country and is vested with the power of judicial review. It is the final interpreter of the Constitution and has the authority to adjudicate disputes between the Union government and the State governments, as well as between the States themselves. The Supreme Court also has the power to hear appeals against the judgments of the High Courts.

Here is a breakdown of why the Supreme Court is the highest constitutional court in India:

1. Constitutionality of Laws:
The Supreme Court has the power of judicial review, which means it can examine the constitutionality of laws made by the Parliament and the State legislatures. It ensures that the laws do not violate the provisions of the Constitution and protects the fundamental rights of citizens.

2. Final Appellate Jurisdiction:
The Supreme Court is the highest court of appeal in the country. It can hear appeals against the judgments of the High Courts, as well as other tribunals and courts in certain cases. Its decisions are binding on all lower courts and authorities.

3. Protection of Fundamental Rights:
The Supreme Court is responsible for safeguarding the fundamental rights enshrined in the Constitution. It can issue writs, such as habeas corpus, mandamus, prohibition, certiorari, and quo warranto, to protect these rights and ensure justice is served.

4. Interpretation of the Constitution:
The Supreme Court has the authority to interpret the provisions of the Constitution. It clarifies the meaning and scope of various constitutional provisions, resolves constitutional conflicts, and provides guidance for the proper implementation of the Constitution.

5. Judicial Activism:
The Supreme Court has often played an active role in addressing social and political issues, especially when the executive and legislative branches fail to act. It has taken suo moto cognizance of matters of public importance and delivered judgments that have had far-reaching implications for the society.

In conclusion, the Supreme Court of India is the highest constitutional court in the country because of its powers of judicial review, final appellate jurisdiction, protection of fundamental rights, interpretation of the Constitution, and its proactive approach in addressing societal issues.

The highest constitutional court in India is the Supreme Court.