One of non registered dealer gst liability date April-2019.but dealer new gst registration composite scheme October-2020 in gst act.
Dealer different date periods april-2019 to September-2020 gst tax payable compulsory.if compulsory sales turnover how to show producer in composite return.
As per your question, the dealer was unregistered till OCT-2020. He got registered in Oct-20 under composition Scheme.
Before registration If turnover was below threshold limit then he was not liable to pay GST earlier because he was not registered in GST hence he is not liable to pay GST for the period before registration.
Now after registration he has to pay GST at a fixed rate on turnover as per composition scheme.