Thank a lot guys, communities are really very helpful.
actually, i found very good thing, once i get connection from home to office , i can easily connect back to home without knowing my home IP.
1)create a tunnel to connect to server abc using SSH from user foo
#ssh -R 988:localhost:22 root@abc.xyz.com (from home)
once u got connection, dnt restart ur home pc
2) Now from root user of server, connect to 988 port using SSH
ssh -p 988 foo@localhost
it will connect to home pc bypassing static ip and router.
Regards,