If rsync is missing from your system, download from IBM the needed rpm file. The needed file can be found at:
http://www-03.ibm.com/systems/power/software/aix/linux/toolbox/alpha.html
Look for the rsync utility and download the rpm. The file name was:
rsync-3.0.6-1.aix5.3.ppc.rpm
and then install it using the below command:
rpm -i rsync_3.0.6_1.aix5.3.ppc.rpm