Step 1: Background of the case.
In Ajay Hasia vs. Khalid Mujib (1981), the Supreme Court held that a society registered under the Societies Registration Act could be considered an "authority" under Article 12 if it is under the control of the government.
Step 2: Principle laid down.
The Court stated that the form of organization (corporation, society, or company) does not matter — what matters is the degree of governmental control.
Step 3: Conclusion.
Hence, a registered society substantially financed and controlled by the government falls within the definition of “State” under Article 12.