15 October 2010
U/s201 is if a person fails to deduct tax at source or after deduction fails to deposit TDS, he is liable to pay simple interest at 1% per month. In your case, you have deducted and paid, but made a mistake in the quarterly return. Thats the reason difference showed in the department.
you just make a detailed letter to income tax department and your tds circle stating that the correction of challan and BSR Code and get the acknowledgement.