The setting up of the Inter-State Council in 1990 was intended to strengthen the federal provisions of the Constitution.

Option 1: Substitute the National Development Council. This option is incorrect because the Inter-State Council was not created to replace the National Development Council. The National Development Council is a separate body that focuses on economic planning and development at the national level.

Option 3: Be an institutional interface between the Judiciary and the Government. This option is incorrect because the Inter-State Council does not serve as an interface between the Judiciary and the Government. Its main function is to facilitate coordination and cooperation among states and between the states and the central government.

Option 4: Provide membership to local customary bodies. This option is incorrect because the Inter-State Council does not provide membership to local customary bodies. Its membership is limited to the Prime Minister, Chief Ministers of all states, and select Union Ministers.

The correct answer is option 2: Strengthen the federal provisions of the Constitution. The Inter-State Council was established to promote a cooperative federal framework and enhance the relationship between the central government and the states. It provides a forum for discussing and resolving inter-state issues and promotes better coordination and cooperation among states.