Below are the steps for dropping database in Oracle RAC.

1. Make cluster database to FALSE

SQL> alter system set cluster_database=FALSE scope=spfile sid='*';

System altered.

2. Stop the db service

Srvctl stop database –d DBACLASS

3. start the database in mount exclusive mode:

SQL> startup mount exclusive restrict
ORACLE instance started.

Total System Global Area 1.0737E+11 bytes
Fixed Size                  7647784 bytes
Variable Size            8.2410E+10 bytes
Database Buffers         2.4159E+10 bytes
Redo Buffers              797655040 bytes
Database mounted.


SQL> select instance_name,status,logins from v$Instance;

INSTANCE_NAME    STATUS       LOGINS
---------------- ------------ ----------
DBACLASS        MOUNTED      RESTRICTED

4.Now drop the database:

SQL> drop database;

Database dropped.

5. Remove the db service from cluster

srvctl remove database -db DBACLASS