Here's the official public notification from IIFA:
"With due regard to the growing concerns around the spread of the COVID-19 virus and keeping the health and safety of IIFA's fans and the general community at large, after consulting the Madhya Pradesh government, the IIFA management, and stakeholders from the film industry it has been decided to postpone to a later date the much-awaited IIFA. Weekend and Awards 2020 celebrations which were originally scheduled at the end of March 2020.
A fresh date and plans for hosting IIFA in Madhya Pradesh will be announced at the earliest.IIFA is fully committed to ensure the safety of the citizens and legions of IIFA fans who travel from across the globe to attend and experience the magic of IIFA. We sincerely regret the inconvenience caused, and hope that all concerned understand the sensitivity of the situation."