Yes, as stated by Mr.A. V. Vishal, you have to use your PAN number not TAN. Generally nowadays the issue of Form 16 or Form 16A has been dispensed with. All taxes paid and TDS are posted in TIN in Form 26AS. The assessing officer can take it from Form 26AS. But if you had not given to your employer your PAN he would not have been able to post it in your name and your payment will not appear in TIN. In such cases the assessing officer can take it from the central records. But he will require TAN of the deductor etc. The required details will be available in form 16A issued by your employer. You have to copy them at the appropriate place in the return form.