Discrepancy in ITR – Section 143(1)

HI Sreekanth, I have received 143(1) from from the IT department (AY 2017-18). There is some discrepancy in this form. In particular, tds that is auto-calculated by IT dept, is different from the one that I mentioned in return form. Now i see that I have mentioned wrong TAN of employer while filing the return under section "Details of Tax Deducted at Source from SALARY [As per FORM 16 issued by Employer(s)]" of excel utility. So, system has not considered the TDS submitted under correct TAN. Could you please advise how can now i correct this mistake as 143(1) is already generated by tax dept.