1. If you are a Taxpayer having received Acknowledgement Reference Number (ARN):
You should be able to download the Provisional Registration Certificate from "Download Certificates" at GST website from 27th June 2017.
2. If you are a Taxpayer, who has saved the enrolment form with all details but has not submitted the same with DSC, E-Sign or EVC:
You will receive the ARN at your registered email ID, if the data given are successfully validated after 27th June 2017.In case of validation failure (data like PAN not matching), you should be able to login at the same portal from 27th June 2017 onwards and correct the errors. You can refer the registered email for details of the errors.
3. If you are a Taxpayer, who has partially completed the enrolment form:
You can login at the portal on the above mentioned date and complete the rest of the form.
4. If you are not an existing Taxpayer and wish to register newly under GST
You would be able to apply for new registration at the GST portal from 25th June 2017.