GST on Rent- December

When a person become liable to register under GST , there could be the gap between effective date of registration( the day on which his turnover exceeded the limit) and the issuance of registration certificate . So the return for the receipts during this gap shall be filed within 1 month from the date of grant of registration ( regidtration date). 

In Your case,if the assessee is granted GST registration on some day in April 2025,then he shall file GSTR 1 and GSTR 3B from 01.12.2024 to the date of registration within 1 month from the date of registration. This is called First Return under GST Act.

In case when his future turnover reduces below the thresold limit, he can surrender the GST registration. But it is suggested that,he can surrender the registration only when he is sure that his turnover will not exceed the thresold limit in the near future from the date of surrender because once his turnover exceeds again, he has to register again under GST which leads to cycle process of registering and surrendering. However, without surrendering his registration, he can continue to file nil returns under GST which is easier than undergoing the cycle of registering and surrendering.

Consult a GST professional  before further action.