Hello @goyalkritika ,
This image option is actually coming from the core image dialog. In the teaser component, this portion is actually reused. So everything under the teaser Image tab is a property of the image component.
If you want to customize it you need to override the image node under the tease component.
for this delete the teaser image metadata. copy the image dialog structure from the image component into the teaser and in the file node, add the required option.