When a private body in the absence of any authorization or delegation chooses to discharge such functions those amount to state functions or public duties which have no legal prohibition per se may be considered falling under the instrumentality of the State.  The BCCI performs a public function, which cannot be termed under the ambit of State mentioned in Article 12.
The law emerged gradually with constant efforts of the courts and now it appears to be finally settled in the view of judgment of a seven Constitution Bench of the Supreme Court in the case of Pradeep Kumar Biswas v. Indian Institute of Chemical Biology  where it was concluded while referring to certain authorities that the tests given in Ajay Hasia Judgment were not rigid, that if a body passes any principle then it is to be declared as an instrumentality of state.
“The main test according to them was of funding and control. Few answers to certain questions can help to identify if the body falls under the definition of the instrumentality of the state.
Is the entire share capital or a major part of it held by the government?
Does the government foot a substantial part of the bill for running the operations of the concerned body?
Is the administration of the body in the hands of the government-appointed directors and are they subject to government control in the discharge of their functions?
Does the state exercise deep and pervasive control over the body in question?
Is the body in question effectively controlled by the government not only in the making of its policy but also in carrying out its functions?
Whether the operation of the corporation is an important public function closely related to governmental functions?
Does the body enjoy monopoly status conferred or protected by the state?”
Though, the above test was not entirely exhaustive but illustrative. If it is not easy to determine the body in question through the tests determined in the classic judgments then it entirely depends on the courts to decide whether the body in question falls under State according to Article 12 or not. The courts have adopted the stance to bring as many bodies as possible within the disciple of the Fundamental Rights as wider the concept, wider the coverage.
1. Zee Telefilms Ltd v. Union of India, AIR 2005 SC 2677.
2. (2002) 5 SCC 111.
3.Jain MP, Indian Constitutional law, (7th ed, 2014) p. 860.