7.
Sir,
First of all as per the sec 31(3) revised invoice can only be issued for the revising the invoices raised between effective date of registration and date of issue of registration.
Further consider a scenario where invoice was raised correctly, igst of 100 was charged on bill however cgst and sgst of 50 each was mentioned on portal due wrong selection of place of supply, in this case my invoice is correct I had to rectify my mistake, which I can do by the amendment option.
In that option where it asks for invoice no you have to mentioned the original invoice number that you want to amend, GSTIN will automatically pick that invoice data, and show to your screen where you can make changes.