If your application is incomplete or incorrect, the GST authorities will send you a notice asking you to rectify the errors. You will need to submit the rectified application within the stipulated time period.
If you are missing or incorrect documents, the GST authorities will also send you a notice asking you to submit the missing documents. You will need to submit the missing documents within the stipulated time period.
If the GST authorities deem it necessary, they may conduct a physical verification of your business premises. This will usually be done if you are applying for a new GST registration or if you are changing your business address.
If you have any pending dues, such as income tax or excise duty, the GST authorities will not issue your GST Registration Certificate until you have cleared the dues.
In general, the GST authorities are committed to issuing GST Registration Certificate within the stipulated time period.