Could someone tell me how to setup VPN for RHEL5 so that i can connect remotely from another location.
You need the sw on and configured with trusted user keys on the target VPN server, and the sw on the client and the matching PPKey. It can run over IPsce IP Protocol or tunneled throught SSH TCP/UDP tunneling: IPsec - Wikipedia, the free encyclopedia
You might just ssh in and tunnel to a vnc desktop.