Yes, you can get a tax refund for previous years. However, to claim a tax refund you must have first filed your income tax return. If you have not filed the income tax return for these previous years then you will have to apply to the Income Tax Department. For a claim of less than Rs 10 lakhs, Principal Commissioners of Income-tax/Commissioners of Income-tax have the right to accept or reject the application. This application must be made to the respective income tax commissioner in person. However,  no application for a claim of refund/loss is accepted over six years from the end of the assessment year for which such application/claim is made. If you have discovered that you are eligible for a tax refund for previous then you can file a revised return. However, you can file a revised return only if you have filed the original ITR before the due date. Furthermore, you can file a revised return 3 months prior to the end of the relevant assessment year. A taxpayer cannot revise an ITR after the completion of the assessment of income.