Happy to help you ... well I would be if I had any idea what you are asking.
A two node RAC cluster is two physical servers, and a storage array, running a single Oracle database of unknown version number: No application and no application server.
EBS R12, I presume, is a totally different product named E-Business Suite version 12.x
They have different architectures, different licensing, different, resource requirements, and totally different management requirements.
So I see two possible answers to your inquiry.
1. You far more clearly explain what you are asking.
2. You burn the two-node RAC cluster to the ground and install the product you want. That said would recommend not putting the application components of EBS on the two node cluster so you will need at least one additional server.