Registration

as per Section 31
Every registered person who has been granted registration with effect from a date earlier than the date of issuance of certificate of registration to him, may issue revised tax invoices in respect of taxable supplies effected during the period starting from the effective date of registration till the date of issuance of certificate of registration:
Provided that the registered person may issue a consolidated revised tax invoice in respect of all taxable supplies made to a recipient who is not registered under the Act during such period:
Provided further that in case of inter-State supplies, where the value of a supply does not exceed two lakh and fifty thousand rupees, a consolidated revised invoice may be issued separately in respect of all recipients located in a State, who are not registered under the Act

in simple terms if you apply for regn within 30 days of getting liable for regn u will take ITC. u may also issue revised invoice and charge GST for intermediate period (i.e. from the date of application to date of grant of regn)

thank you