Yes, even though income is solely from fixed deposits and saving bank interest, an individual whose income exceeds the basic exemption limit during a financial year must file an income tax return in India.
If the bank has deducted TDS and your income does not exceed the basic exemption limit then you must file a tax return to claim a refund on excess TDS deducted.
You can file your Income tax return using ITR-1, an individual needs to fill information under these three heads: Income from salary/pension, Income from house property and Income from other sources.
Income from other sources includes all the residual income that cannot be placed in other heads of income. These usually include interest income from savings bank accounts, post office savings accounts, fixed deposits, recurring deposits, family pension etc.