An employer deducts TDS on salary at average rate according to applicable tax slab.An employer will have to deduct TDS, if you have a liability towards income taxes. (This is calculated on the basis of your income & after considering any deductions & exemptions that you are eligible for). So just to ensure that TDS don't get deducted in excess, you should declare all your tax saving investment to your employer.To conclude: If after considering all the eligible deduction & exemption, if you still have a liability towards, you cannot avoid TDS by employer.TDS is just a collection of taxes by your employer on your behalf, even if the employer does not do so, you will still have to pay your due income tax at the time of filing ITR. If TDS is over deducted, you can always claim a refund.Trust this clarifies your queryHappy reading!