Mismatch in gstr1 and gstr3b liability

I have added amend some invoice of B2C of the previous financial year to B2B in GSTR1 of Sep 18 month. But forget to reduce the amount form "Amend B2C" section. Because of that there is mismatch of liability in GSTR1 and GSTR3B. In GSTR1 the liability is showing as 84 lakhs but as per my outward sales and GSTR3B it has to be 53 lakhs. What can we do now