After installing Oracle Clusterware, as described in Oracle Grid Infrastructure Installation Guide for your platform, you can install Oracle RAC Database software.

• About Image-Based Oracle Database Installation
  Starting with Oracle Database 18c, installation and configuration of Oracle Database software is simplified with image-based installation.
• Deciding Between Multitenant Container Databases and Non-CDBs in Oracle RAC
  Review the information to decide how to deploy your Oracle Database using the CDB or Non-CDB options.
• Installing Oracle RAC and Oracle RAC One Node Databases
  Understand the process to install Oracle Real Application Clusters (Oracle RAC) and Oracle RAC One Node Databases.
• About Deploying Oracle Databases Using Rapid Home Provisioning
  Rapid Home Provisioning provides a standardized approach for provisioning, patching and upgrading software homes on any number of nodes from a single cluster.