Here is a detail procedure for revocation of GST registration under different situations

1. When the registration has been cancelled by the Proper Officer (Superintendent of Central Tax) on his own motion and not on the basis of an application ,then the registered person, whose registration has been cancelled, can submit an application for revocation of cancellation of registration, in FORM GST REG-21, to the Proper Officer (Assistant or Deputy Commissioners of Central Tax), within a period of thirty days from the date of the service of the order of cancellation of registration at the common portal, either directly or through a Facilitation Centre notified by the Commissioner:
2. If the registration has been cancelled for failure to furnish returns, application for revocation shall be filed, only after such returns are furnished and any amount due as tax, in terms of such returns, has been paid along with any amount payable towards interest, penalty and late fee in respect of the said returns.
3. On examination of the application if the Proper Officer ( Assistant or Deputy Commissioners of Central Tax) is satisfied, for reasons to be recorded in writing, that there are sufficient grounds for revocation of cancellation of registration, then he shall revoke the cancellation of registration by an order in FORM GST REG-22 within a period of thirty days from the date of the receipt of the application and communicate the same to the applicant.
4. If on examination of the application for revocation, if the Proper Officer (Assistant or Deputy Commissioners of Central Tax) is not satisfied then he will issue a notice in FORM GST REG–23 requiring the applicant to show cause as to why the application submitted for revocation should not be rejected and the applicant has to furnish the reply within a period of seven working days from the date of the service of the notice in FORM GST REG-24.
5. Upon receipt of the information or clarification in FORM GST REG-24, the Proper Officer (Assistant or Deputy Commissioners of Central Tax) shall dispose of the application within a period of thirty days from the date of the receipt of such information or clarification from the applicant. In case the information or clarification provided is satisfactory, the Proper Officer (Assistant or Deputy Commissioners of Central Tax) shall dispose the application as per para (iii) above. In case, it is not satisfactory the applicant will be mandatorily given an opportunity of being heard, after which the Proper Officer (Assistant or Deputy Commissioners of Central Tax) after recording the reasons in writing may by an order in FORM GST REG- 05, reject the application for revocation of cancellation of registration and communicate the same to the applicant.
6. The revocation of cancellation of registration under the State Goods and Services Tax Act or the Union Territory Goods and Services Tax Act, as the case may be, shall be deemed to be a revocation of cancellation of registration under Central Goods and Services Tax Act