differece between revised and modified return

Revised return.... that is filed u/s. 139(5) of IT act..

Modified or removing defect in already filed return is as per sec. 139(9) of IT act..

It may be sometimes used for rectified return u/s. 139(4) of IT act....

As per the proper interpretation of the language of Income Tax Law, there are 3 similar but not same returns:

1) Revised Return: Filed u/s 139(5) by assessee itself on suo moto basis for revising return in case of any omission or wrong statement filed earlier in ROI u/s 139(1), 139(3) or 139(4). Time Limit is upto end of relevant assessment year.

2) Rectified Return: Filed in response of intimation by AO of the Defective Return u/s 139(9). Time Limit is within 15 days of intimation by AO (which may be extended). 

3) Modified Return: Filed as an effect to Advance Pricing Agreement u/s 92CD in case APA applies to any prior period of which ROI had already been furnished earlier but the APA has been signed later. Time Limit is within 3 months from the end of the month in which APA was entered into.

Note: Please refer the below attached file for the above referred income tax sections (may refer only highlighted part).