Cancellation of GST Registration on Closure of the Busines

Yes you can but keep filing nil returns till then.

Yes cancellation can be done

Agree with Altamush.

A taxpayer whose GST registration has either been cancelled or surrendered is required to file GSTR-10. it is a statement of stocks held by such taxpayers on the day immediately preceding the date of cancellation. It is a one-time final return. It should be filed within three months from the date of cancellation or the date of the cancellation order, whichever is earlier.

Agree