Filing return without payment of self assessment tax is considered as defective return. So, either pay the tax online through net banking which can be done 24*7 and file return or if you want to pay tax through challan then you have to wait for filing return till you file challan on banking day.
I have received the letter from income dept for non filing of I T return for the A Y 2013-14, for the bank interest of 601312/- how much income tax ihave to pay for the F Y 2012-13 & can i file I T Return now?,