Hi Dhaval,
I moved your question to the Remoting users forum and turned it into a discussion instead of an article.
In AS 5.1, Remoting is configured in $JBOSS_HOME/server/$CONFIG/deploy/remoting-jboss-beans.xml. To read about the new Remoting configuration syntax, see Section 5.1.1.3. "Declarative configuration: POJOs" of the Remoting Guide at http://docs.jboss.org/jbossremoting/2.5.3.SP1/html/.
I can't tell you anything about transaction configuration, but I see a transaction-jboss-beans.xml file in the same directory.
-Ron