When start the Oracle database it is giving the error related to control file.

SQL> startup:
ORACLE instance started.
Total System Global Area 1543567850 bytes
Fixed Size 138322 bytes
Variable Size 865789932 bytes
Database Buffers 5678889900 bytes
Redo Buffers 39803967 bytes
ORA-00205: an issue occurred in identifying the control file

Cause: Control file is not available or may be corrupted

Solution: Steps for Restore the control file from backup in Oracle

Startup the Database in NOMOUNT Mode 

SQL> startup nomount; 
SQL> select instance_name, status from v$instance;
INSTANCE_NAME STATUS
------------ ------
TESTDB STARTED 
SQL> exit;

Connect to the Target Database and restore the control file backup

RMAN > connect target / 
RMAN> restore control file from autobackup 

Mount the Database:

RMAN > alter database mount; 

Restore and Recover the database:

RMAN> restore database; 
RMAN> recover database;

Open the Database with Resetlogs:

alter database open resetlogs;