This is a very simple setup of RAC implementation...
However this network stack states:
This is the node's hostname, i.e server's name
IP Address eth0: 192.168.0.101 (public address)
Default Gateway eth0: 192.168.0.1 (public address)
This is the primary nic for this node as it includes the gateway, and will be exposed to the users over your network
IP Address eth1: 192.168.1.101 (private address)
Default Gateway eth1: none
This is the secondary nic in server which will be used for SAN or storage connection, you may also consider it as internal nic which will only be used by the servers for communication
Hope this helps!
The private address/ip will be used for internode communication as the cluster interconnect. It will be not available to clients.
As your System Admin to configure both the public and private IPs.