I have below schema element. But its not rendered as a check box . I want to select more than one element in the given enum. Please let me know how to do that
Which version of JSON Forms and renderer set are you using? The schema posted by @chathuraa should work for example with the latest React Material renderers.
This feature is not (yet) supported by the off-the-shelf Angular Material renderers, see here for the renderer sets overview. If you need it you need to add it yourself with a custom renderer. If you create such a renderer you could think about contributing it back to the main repository.