GSTR 3B - Part Invoice GST payment clarification

Hi,

Due to COVID-19 my departed commercial tenant told he will pay me only half month's rent on 24.03.2020 for the month of March 2020 and based on that I paid only half rent but the March month's GST invoice issued to him had entire month's rental value. However during his departure from the rental property on July month he paid the full month's rent for March 2020.

How should I rectify this please help me.