You can use "wso2.anonymous.role. Add that role to schema resource in resource browser.
"The "wso2.anonymous.role" is a special role that represents a user that has not logged into the WSO2 Governance Registry Management Console. Granting "Read" access to resources for this role would mean that you do not require authentication to access resources using the respective Permalinks. The "everyone" role is a special role that represents a user that has logged into the WSO2 Governance Registry Management Console
Refer http://docs.wso2.org/wiki/display/Governance460/Managing+Role+Permissions