Regarding Registration

First, you have to pay all GST Liability & Late Fees (if any) then you have to fill Form REG-16 for cancellation of GSTIN.

Reg 16 from which Site or it is manually

Make sure that all the GST Returns are filed up to date and no liability is pending with the Department before you proceed to cancel your GST Registration.

After you file all your GST Returns ( with the applicable late fees, if any ) , then you will find the option of cancellation of GST Registration in the portal.

You have to file FORM GST REG-16 ( Application for Cancellation of GST Registration ).

I opted for Quarterly GST Return and 6 month nil return completed in July month. GSTR 3B is filed but can not file GSTR 1 as due in Oct month. Also there is late fees of June GSTR 1 Which will be paid in subsequent GSTR 1.

If you had chosen as voluntary registration then you can proceed for cancellation only after one year from the date of registration.

Till one year No penalty will be levied as no commencement of business within 6 month and filed nil return.