@ Lalit..since you have booked the whole amount of Audit Fees(inclusive of service tax) on 31.03.2011 therefore you were required to deduct TDS on the same @ 10% & deposit the same before 30th April 2011...now you have not done that therefore you'll have to deduct TDS now while making the payment & deposit the same alongwith interest for late deposit....interest will be calculated as follows:
[(1% from the date on which tds was deductible to the date it was actually deducted) + (1.5% from the date it was actually deducted to the date of payment)]..
since you haven't made any provision for interest on tds in the books for the year ended 31.03.2011 therefore while paying the interest debit prior period expenses instead of interest on tds.....
your balance sheet which most probably would have been signed by now...just see the computation of income working to know whether audit fees has been disallowed or not....
if tds is not deposited before the due date of filing of return then this expense will be disallowed in the current year & allowed in next year as per section 43B of IT Act...!!!