Hi Vikram,
Add the caas.json.jsp file in the project and update its content as below:
/apps/cq/Page/caas.json.jsp
<%@include file="/libs/cq/Page/proxy.jsp" %>
Update the workspace filter so changes are picked up:
<filter root="/apps/cq/Page">
This should work. You can add multiple selectors with this way.
Another solution is to combine your custom selector with the OOTB model selector e.g model.caas