When you realize that some error has occured after you have filed your return, then you have to rectify your mistake.  For the purpose of rectifying your mistake you are required to file a revised return.  So revision of return is a function of rectification.

Giridhar ji is right.

ok but there is some other provision in IT for rectification which is other than revised return.I want to know about that.

yeah i think you are confused with section 154. those provisions are for rectification of assessment orders not for rectification of return of income

Revised Return can be filed only if you have done any mistakes(omissions or commissions) in your original return of income filed. In otherwords revised return is filed  to rectify your mistakes committed in your original return of income.

Rectification  is applied only if you have find any error in the order passed by the Department. In others rectification is sought only if you have find any mistakes in the order passed by department. 

Revised return - is filed to rectify the mistakes made in the original return filed by the assessee

Rectification  - is filed to rectify the mistakes in the order passed by the department.

Rectification is related to order passed by Assessing Officer. Only those mistakes which are apparent from record (in regard of which two views are not possible) can rectified u/s 154 upto 4 years from the end of the financial year in which order sought to be rectified was passed !!

Whereas REVISED is used in context of RETURN.

As such if there is any error - for rectification you have to file the revised return. But durign the assessment (before order) you can make application of assessing office for adding/deleting some matter as rectification of mistake. To accept/reject the application is in the powers of assessing officer.

My bank did not show a TDS in 26AS earlier but now they have included it in 26AS. I have already filed ITR before this TDS inclusion in 26AS.

The TDS was on a Previous Interest i.e. they had shown Interest income in 26AS but not the TDS.

Should I file Revised Return or Rectification Return?

You should filed revised Return and if due date is lapse then thow the said inciiin next year