1) Income disclosed by you in the ITR is same as assessed income, and if amount of TDS as submitted in ITR is different from the amount of TDS allowed, then verify the 26AS and if amount of TDS in 26AS is same as TDS allowed, then ask the remaining parties who had issued the TDS certificates to rectify their return. Your PAN may not be mentioned correctly in the return. And also file rectification u/s 154 of the Income Tax Act, 1961 with your ITO.
2) Income disclosed by you in the ITR is different from the assessed income, then there will be the need to find out what the AO has allowed and what not. Then in that case you need to go in the appeal.
12 December 2010
If you are certain about the mistake, try either rectification under section 154(2)(b) or appeal under section 246A of the Income tax Act,1961.