Tax exemption for Tamil Nadu Pollution Control Board: specified non commercial fees notified as exempt subject to conditions and filing requirement. Central Government notifies Tamil Nadu Pollution Control Board for exemption of specified income, listing categories such as consent and authorization fees, analysis and survey fees, reimbursements for monitoring programmes, training fees without profit element, RTI fees, public hearing fees, sale of non commercial law books and scrap, interest on staff loans and deposits, cess reimbursement and appeal fees, and miscellaneous receipts; subject to conditions that the Board shall not engage in commercial activity, the nature of activities and income remain unchanged, and the Board files its return of income as required; notification applies to specified assessment years.