Revise return and rectified return

Revised return can only be filed if you have filed the return within the due date ie for FY 14-15 due date was 31.7.15 so u can file revised return upto 31.3.17 if u had filed the return within 31.7.15. However if u didnt file return within due date u cannot file a revised return, only then u can go for rectification u/s 154 for any mistake etc

rectification is correction of tax details