Revised Return after Refund is Received ?

Yes you can file revised return before 31.3.21

Can it be filed online and what will be status of refund already received and additional to be received on Missing 80c amount. Is there any penalty for this ?

Mr. prem Gupta you are not eligible to filed Revised because your return is already processed and you got your refund. In case your return is not processed then you revised n number of time without any time limit till the return is processed. and sourav 31march of the assessment year is the due date for belated return as per section 139(4).

It is possible. will get additional refund pursuant to revised return.

Kindly explain

It is totally possible to file a revised return after the notice or intimation has been received by the taxpayer under Section 143(1) by the Income Tax Department. The revised return can be filed as per the Section 139 (5) of the Income Tax Act.

Dear Kapadia ji please ask your senior or your colleagues for revised return process. after processing of return it is not possible to revised except your case is under security.

The word assessment used in section 139(5) will refer to assessment made under section 143(3) and section 144. Assessment made under section 143(1) will not be treated as assessment for this purpose as such return can be revised even after the intimation under section 143(1) has been served.

of course you can, I wish you good luck