Cause:

While you restore a database from source database to new database , the controlfile backup should be taken from source database and restored in new database for reconstructing the whole database with consistent scn. If the database name in destination is different,then we need to change the database name in controlfile

SQL> startup mount;
ORACLE instance started.

Total System Global Area 1509949440 bytes
Fixed Size                  2924640 bytes
Variable Size             956305312 bytes
Database Buffers          536870912 bytes
Redo Buffers               13848576 bytes
ORA-01103: database name 'ORCL' in control file is not 'ORCLDGP'

Workaround:

Change the database name and db unique name in controlfile using spfile

SQL> show parameter db_name

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
db_name                              string      ORCLDGP

SQL> alter system set db_name=orcl scope=spfile;

System altered.

SQL> show parameter db_unique_name

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
db_unique_name                       string      ORCL

SQL> alter system set db_unique_name=ORCLDGP scope=spfile;

System altered.

Bounce the database

SQL> shu immediate;
ORA-01507: database not mounted


ORACLE instance shut down.
SQL> startup mount;
ORACLE instance started.

Total System Global Area 1509949440 bytes
Fixed Size                  2924640 bytes
Variable Size             956305312 bytes
Database Buffers          536870912 bytes
Redo Buffers               13848576 bytes