Vendor filed invoice less amount in GSTR1

our one supplier has filed his supply in his R1 but with less amount i.e. Invoice value is correct but Taxable & GST amount wrongly filed with lesser amount. 

supplier has already modified his R1 with another invoices & now can not change such invoice. now how can i reconciled GSTN invoice with our ERP.

can i take cash of differences or writte-off such difference amount or something else much batter?