Hi Harish,
You will find all the existing views from SYS.VIEWS
SELECT * FROM SYS.VIEWS
There is another system view CATALOG_OBJECTS_CREATED_BY_REPOSITORY_ACTIVATIONS of schema SYS_REPO which gives information about all objects of repository. You can filter based on the field REPOSITORY_OBJECT_TYPE to see only activated views.
Regards,
Bhavin