The department responsible for budget preparation and financial management in Tamil Nadu is:

Finance Department
Planning Department
Revenue Department
Treasury Department

The correct answer is: Finance Department.

The Finance Department is responsible for the preparation of the budget and the management of the state’s finances. It is also responsible for the collection of taxes and other revenue, and for the disbursement of funds to the various departments and agencies of the state government.

The Planning Department is responsible for the formulation of the state’s development plans. It is also responsible for the monitoring and evaluation of the implementation of these plans.

The Revenue Department is responsible for the collection of taxes and other revenue from the state’s citizens and businesses. It is also responsible for the administration of the state’s tax laws.

The Treasury Department is responsible for the safekeeping of the state’s funds. It is also responsible for the issuance of checks and other financial instruments on behalf of the state government.

In conclusion, the Finance Department is responsible for the budget preparation and financial management in Tamil Nadu.