Hi Ruzica,
I work for Red Hat on the SAP relationship. To your question, short answer is that you will need "Red Hat Enterprise Linux for SAP Business Applications" Subscription (In short RHEL for SAP) instead of a regular RHEL6. Please check the RHN KnowledgeBase article for details on RHEL for SAP, including important info. on support and locales. https://access.redhat.com/knowledge/node/34169
Please contact your local Red Hat sales for subscriptions to RHEL for SAP. There is no additional cost. And to switch, there is no need to rebuild your OS. What you will need to do is to subscribe your server to the "RHEL for SAP" child channel and start receiving rpms including locales.
More information on Red Hat products and solutions can be found on "SAP on Red Hat" SCN page: http://scn.sap.com/docs/DOC-37811
Should you have further question please feel free to contact sap@redhat.com
Regards,
Sherry