Hi,
I want to use Localize option in “Image” component in the inspector of Unity 3D, not Texture 2D or TMP, for the purpose of showing different images to the users in specific country.
Is there any solution for this? or any future update plan considering Image Localization?
Yes we support asset localisation. In the current version we have a table per asset type and support sprites, texture 2d and audio out of the box however in the next release we will have a single table type(Asset Table) that can take any asset type 
The Localize options are just shortcuts at the moment that add a Localize Component and set it up with events. If theres no option then add the component yourself and hook up the events. In the future we hope to get rid of the Localize Component and have the options directly in each components(Where possible).
We are aiming to have the next release ready for September (Unite Copenhagen).