Thanks Phobus for the reply
Well what i did was go to the destination machine. update its /etc/hosts file with the Service IP and hostname of the cluster...
In the cluster hacmp settings for Resource Group I added my mount point where it asks for
"FileSystems/Directories to export (nfsv3/4) [/testmnt]"
and syncd the cluster from Extended Config>Extended Verification and Synchro
after this I went back to the destination machine and tried to mount nfs and lo!
Regards,