GSTR-1 is a return that specifies outward supplies made by an assessee over a period of one month. Supplies made to a tax deductor are also covered and hence have to be reported in Form GSTR-1.Separate section may be provided in the return for supplies made under section 51 of the CGST Act but mostly such supplies are reported in supplies made to B2B parties.In GSTR-3B, the amount deducted as TDS is reflected in the E-Cash Ledger and hence, is deductible while making payment of taxes.