Please make sure you have the 'Open Graph - JomSocial' plugin enabled. If it is disabled, the available JomSocial objects and actions won't show up in the list when you're trying to create the entries.
Additionally, during installation JFBConnect detects whether JomSocial is installed on your site and only adds the plugin if JomSocial was found. If JomSocial was installed after JFBConnect, you can reinstall JFBConnect to get the appropriate plugins installed or you can find them in the com_jfbconnect zip file under /packages/plugins/opengraph.
-Melissa
JFBConnect: Open Graph - Objects - Can't choice Jomsocial
