Revised return

No return cannot be revised as it is already processed u/s 143(1). And hence no deduction u/s 80GG will be allowed. 

However wrt refund, log on to efiling website, in that go to "my account" and in that click on refund reissue request, and punch in all the details that is given in your 143(1) intimation. Then a new screen appears, wherein it asks whether to change bank a/c derails. Select yes. And then rectify the correct ifsc. And then press OK.

Its done. Whatever refund you were eligible for in 143(1) will be credited after the request is processed

@ Manoj Singh:

Sorry , need to correct myself. Actually got to know it now. 

You can still revise the return, claim Sec 80GG and write the correct bank details now. Actually 143(1) is just a summary assessment or just an intimation and hence assessment is still not completed. You will get the refund as claimed in your reved return

Sorry for the wrong comment made earlier.