Your income tax return cannot be submitted to the tax department, unless you have paid tax dues in full. Sometimes, you may see tax payable at the time of filing your return. This income tax can be paid online or through offline challan [ deposit into the bank by mentioning the challan details such as BSR Code, Date of Challan, Amount deposit etc]. Incase, you are paying tax after due date, interest under section 234B and 234C will also have to be paid along with your tax due.