Notice U/s 143(1)a Outstanding demand

If you have received any notice, reply the same by disagreeing the demand, and submit the details of challan no. with the amount & date of payment.

If the demand is for interest charged over any earlier paid demand, you are require to pay the same.

OK.  Reply stating that the amount already paid by deductor, and submit copy of TDS certificate &/or form 26AS.

Yes, in that case you will have to file rectification request offline, with your Jurisdictional AO.