Gst Registration on single pan no

No.

Because all the registrations in different states (though same PAN) are different and independent.

If you have different registrations in different  states, the ITC will be availed by that particular state only. You cannot club all the ITC and then pay taxes.... All the separate registrations will be treated as separate entities.

Assessees who are not able to migrate to GST due to RC cancelled(PID cancelled) error or PID is still showing awaited, are requested to send an email to cbecmitra.helpdesk @ icegate.gov.in from your registered email ID (against ACES registration) by quoting the email subject line "Provisional ID required for GST Migration" along with the below mentioned details.