as of now many note 9 devices are facing display discoloration issue after march 2020 update. If your device is working fine do not rush for latest update, keep patience till they fix this issue entirely.
If you want to take a chance then download indian Firmware from sammobile.com or using Frija Tool
then Flash via odin.
you can also try resetting your phone. do not remove your sim card while performing reset.
once the device is formatted you see prompt option to change your region to India.
once it changes to india you'll receive latest OTA notification.