Cancellation of gst registration

yes u can but the stock also nil of books of account.. Then no liability to charge tax.. otherwise u can file cancellation of business.. or gstr10 file your return

Yes...

Persons who have taken Registration Voluntarily under GST [ u/s 25(3) of the CGST Act 2017 ] can cancel their GST Registration even if 1 year has not elapsed from the date of Registration...

So Go Ahead...

Just remember that you cannot proceed to cancel your GST Registration unless all your Returns have been filed successful .

no cannot be cancelled for a year