you have both the options mentioned above. Either you can file a rectification u/s 154 mentioning the reason for rectification that the details of return filed actually pertains to A.Y. 2011-12 and not A.Y. 2010-11 and accordingly TDS against such income was also claimed in the return. Correct data in your return for A.Y. 2010-11 and upload that corrected xml file while filing online rectification request if you have filed return online and if you have filed paper return then just give this letter mentioning actual income for the A.Y. 2010-11 and then file return for the A.Y. 2011-12 with correct data.
or
you can simply revise your return for the A.Y. 2010-11 which was wrongly filed. You should mention the correct income of A.Y. 2010-11, if any, in that return or you should file NIL revised return and then file corrected A.Y. 2011-12 return.
for any further clarification feel free to write to me.