The correct answer is: Director of Census Operations.
The Director of Census Operations is the head of Census operations at the state level in Tamil Nadu. He/She is responsible for the planning, execution, and supervision of the census in the state. The Director of Census Operations is appointed by the Government of India and is usually a senior Indian Administrative Service (IAS) officer.
The Chief Minister is the head of the state government and is responsible for the overall administration of the state. The Governor is the head of state and is appointed by the President of India. The Registrar General & Census Commissioner of India is the head of the Census operations in India and is responsible for the planning, execution, and supervision of the census in the country.
The Director of Census Operations is the most important official in the state for the census. He/She is responsible for the success of the census in the state.