In case of local sales or inter-state sales both parties i.e seller and buyer are registered. If consignor (seller) unable to make E-waybill for any reason then consignee (buyer) can make the E-waybill by showing Inward supply. I heard about this that in case of purchase from unregistered person this inward supply E-waybill should make. But in my case both parties are registered, so can buyer make E-waybill on behalf of seller by showing Inward supply.