If it's RHEL then first ensure the machine has access to RHN.
If it's RHEL and you won't buy RHN access then convert to CentOS or another (Enterprise?) Linux of choice.
Else check your /etc/yum.repos.d/update configuration for the baseurl directive and see if you can access the URI with cURL, wget, (e)links or whatever else.
*Please note that unless you was raised by baboons courtesy and netiquette apply always, so saying "Please give" would be preferred over just "give" for the more favorable impression it leaves.