I rectified the error finally.
With yum rpm, additional dependency rpm's also needs to be installed. Which I was missing.
There are 5 rpm's in total including yum rpm.
Downloaded from "http://mirror.centos.org/centos-5/5/os/i386/CentOS/", these are :
Install all these ( as root )together with
To check for installation run,
The above five rpm's should come.