Hello Venkat,
I'm working with postgresql and hibernate without any problems.
here's my db config
Code:
<hibernate-configuration>
    <session-factory>
        <property name="hibernate.connection.driver_class">org.postgresql.Driver</property>
        
        <!-- DB-Einstellungen für den Produktivbetrieb -->
        <property name="hibernate.connection.url">jdbc:postgresql://127.0.0.1/dbname</property>
        <property name="hibernate.connection.username">username</property>
        <property name="hibernate.connection.password">password</property>
Maybe it is a problem with postgres. The pg_hba.conf is always worth a try. Maybe you missed something in your connection setting and postgres doesn't accept connections from your ip or user.
Yours
Christian