The command to change port number is pretty simple:
sync -av -e 'ssh -p PORT-NUMBER-HERE' /path/to/source user@backup1.example.comBackup /home/vivek to server1.nixcraft.net.in at port number 5000, enter:
rsync -av -e 'ssh -p 5000' /home/vivek backupop@server1.nixcraft.net.in
See also:
man rsync
REFERENCES
http://www.cyberciti.biz/faq/unix-linux-bsd-osx-change-rsync-port-number/