Dear Santu
If u had booked expenses in March'11 and deduted TDS in April then rate of interest charged is 1% p.m. from the date it was deductible to the date it is deducted. There will be no interest on deposit as u hav deducted in april and deposited before 7th may. But expenses that u had booked in march'11 will not be allowed in F.Y. 2010-11.