Gst implication on an auction sale & scrap sale

hello karthikin raju... banks and nbfc are only custodian of old gold jewellery. .so the are not allowed to trade in it..they can auction on as is where is basis ...only..and make bidders bill as old gold jewellery. no gst must be charged....as custodians are not allowed to trade in sale or buying of gold jewellery by RBI.if they charge they will have to payback the gst to their clients with penalty and interest by law.

hi everyone 

one of my client is govt entity excise department have seized motor vehicles. seized while these were using in smuggling activities now department is going to sale these vehicle through auction  what will be the GST implication on these activites