GST and IGST/ SGST Queries

Mr. A is a car dealer, buying Used cars only from bank auctions

Now the problem is bank has its yard in Haryana and cars is also registered in Haryana, while purchasing bank issue invoice in Cgst and sgst.
(Lets say if winning bid is 500000, it includes Gst- {sale price+ Gst= 5Lac} "Query No.1")

Dealers takes delivery of the vehicle brings it to Delhi for paint, polish, etc & sells it to a Party in Other state from its delhi office.(Query 2)

Dealers responsibility is only getting the vehicle NoC from the concerned authority, delivery will be in delhi or sometimes from banks yard itself (Query 3)

Q1. Dealers will be covered in RCM, if yes. Can dealer use Gst paid during auction and claim ITC under RCM?

Q2. Will the invoice be issued in cgst plus Igst or sgst if delivery is from delhi office?

Q3 if the delivery is from banks yard(vehicle is sold before dealers brings vehicle to his office) then sgst or igst will be used in invoice, what is the penalty is we mix it up?

Q4 What happens if we sell it to party in Haryana, then sgst or igst invoice should we issue?