To change the OBIEE 11G browser Title name to your custom text Open productmessages.xml from <Middleware_Home>\Oracle_BI1\bifoundation\web\msgdb\l_en\messages. Search for kmsgProductPortal attribute and change its value with your custom text.
<TEXT>Shiva BI Interactive Dashboards</TEXT>
save it and stop and start the Opmn to restart all OBIEE 11G services. Once the services are up, you will see the changed browser title as shown in below picture.