Revival of GST registration

My client migrated from VAT to GST but due to dsc not verified so
proper officer(tax authority) cancelled my client's registration
but after new scheme from 6th August started regarding revoke of cancellation of registration(old GSTIN)
my client submitted application under the new scheme and he received notice of clerification before 4th sep
but on 2nd Sep I have tried to submit clarification on Portal so message popup that your notice period already expired and on 6th sep I have received order of application rejected so what to do to revive my client's old GST number ?