Hmm, I am sorry, I don't  see what I can do for you...can you rephrase your question a bit?

Anyhow,

Mod_cluster uses UDP multicast olny for advertising the balancer's presence.

Balancer <----> Nodes communication as to client's requests or MCPM messages is TCP/IP...

If your enviremoment does not support multicast, just don't use Advertising feature and rely on proxy-list configuration (tells the node where to look for balancers).

To answer this question:

how we configure unicast in jboss

Look into standalone-ha.xml and you should see:

<subsystem xmlns="urn:jboss:domain:jgroups:1.1" default-stack="udp">

            <stack name="udp">

                <transport type="UDP" socket-binding="jgroups-udp"/>

                <protocol type="PING"/>

                <protocol type="MERGE3"/>

                <protocol type="FD_SOCK" socket-binding="jgroups-udp-fd"/>

                <protocol type="FD"/>

                <protocol type="VERIFY_SUSPECT"/>

                <protocol type="pbcast.NAKACK2"/>

                <protocol type="UNICAST2"/>

                <protocol type="pbcast.STABLE"/>

                <protocol type="pbcast.GMS"/>

                <protocol type="UFC"/>

                <protocol type="MFC"/>

                <protocol type="FRAG2"/>

                <protocol type="RSVP"/>

            </stack>

            <stack name="tcp">

                <transport type="TCP" socket-binding="jgroups-tcp"/>

                <protocol type="MPING" socket-binding="jgroups-mping"/>

                <protocol type="MERGE2"/>

                <protocol type="FD_SOCK" socket-binding="jgroups-tcp-fd"/>

                <protocol type="FD"/>

                <protocol type="VERIFY_SUSPECT"/>

                <protocol type="pbcast.NAKACK2"/>

                <protocol type="UNICAST2"/>

                <protocol type="pbcast.STABLE"/>

                <protocol type="pbcast.GMS"/>

                <protocol type="UFC"/>

                <protocol type="MFC"/>

                <protocol type="FRAG2"/>

                <protocol type="RSVP"/>

            </stack>

        </subsystem>

Just switch the stack to tcp:

default-stack="tcp"

Afterwards, you will probably have to change MPING to TCPPING with static node configuration.

The topology is clear, so what is the question now?

To avoid using multicast for mod_cluster, use attribute proxy-list in mod-cluster-config element [1].

[1] http://docs.jboss.org/mod_cluster/1.1.0/html/java.AS7config.html#ModClusterSubSystemConfiguration

Right, you will have to use static configuration here.

mod_cluster uses multicast to discover the jboss nodes. This won’t work in production or staging as jboss is inside the firewall and thus on a different VLAN. Multicast does not work across VLANs.How to overcome this situation and another thing is I am using jboss EAP6.0. domain level

To do this, if you prefer editing XML files, edit the mod cluster configuraion and configure attribute proxy-list like this:

<mod-cluster-config proxy-list="10.0.1.2:6667"/>

It is comma-seprated list of host:port of the load-balancer to register the  AS node with.

here 10.0.1.2:6667 is Loadbalencer url ?

No exactly URL, but HOST:PORT combination. If you have it under different context you would need proxy-url which if defined, this value will be prepended to the URL of MCMP commands. You can likely ommit this.

in jboss level we need any configuration is required or not ?

Yes, this is at JBoss level. You need to tell the JBoss AS which load-balancers to register with if multicast doesn't work for you.

where we add proxy list url in httpd.conf or domain.xml

Open up domain.xml and look for "mod-cluster-config" -- there you will configure this.

I seen some configuration in jboss console --- > mod_cluser that is any related with load balencer(mod_cluster) ?

Yes, thats the same configuration in the console. You can configure this from the console if you prefer that.