Hi Arun,
For Oracle integration,you need to change Oracle dialect,username,password,url in respective persistence.xml files.
For example-
<property name="hibernate.dialect" value="org.hibernate.dialect.Oracle10gDialect"/>
<property name="hibernate.connection.driver_class" value="oracle.jdbc.driver.OracleDriver"/>
<property name="hibernate.connection.url" value="jdbc:oracle:thin:@localhost:1521:xe" />
<property name="hibernate.connection.username" value="jbpm"/>
<property name="hibernate.connection.password" value="password"/>
And also make sure that oracle jdbc jar(e.g. oracleJDBC-10.jar ) is in class path which can also be configured in ant script as I had mentioned in my old post date Dec 1, 2010 7:07 PM under section "Installer build file change is given below"