It is always recommended to create database in RAC using DBCA only (GUI) . But for some reason, if  you want to create manually, then follow below steps:

In this article , we will create a database in a 2 node rac. Database name will be DBATST with instance names DBATST1,DBATST2

1. Prepare a init file:(as below)

2. Start the db in Nomount:

3. Create the database :

4. Create another undo tablespace for other node:

5. Create USERS tablespace:

6. Create CATALOG and CATPROC components:

7. Run below additional scripts:

8. Create JVM component:

9. Create cluster related views:

10. Enable archive log mode:

11. Add the redo thread for another node :

12. add the cluster_database parameter in init file.

13. Create spfile in diskgroup:

14.Update the initDBATST1.ora in dbs location

15. Run utlrp.sql

16. Shutdown database:

17. add the database to CRS:

18. Start the database: