How to move or rename a datafile of a tablespace in oracle database

Datafile movement 12c Database Code

ALTER DATABASE MOVE DATAFILE '+DATA/orcl/datafile/orcl_custom.702.836915343' TO '+DATA_BKP/orcl/datafile/orcl_custom.702.836915343';

In 12c Database you need not have to make the datafile offline to do the changes. You can do it online. It is a new feature. 

For other version you need to follow the below steps.

step1: Bring the datafile offline

ALTER DATABASE DATAFILE '+DATA/orcl/datafile/orcl_custom.702.836915343' OFFLINE;

step 2: Nove the datafile to new location

rman target /

COPY DATAFILE '+DATA/orcl/datafile/orcl_custom.702.836915343' TO '+DATA_BKP';

step 3: Rename the datafile with new details with alter database  

ALTER DATABASE RENAME FILE '+DATA/orcl/datafile/orcl_custom.702.836915343'

TO '+DATA_BKP/orcl/datafile/';

step 4: Make a copy of datafile

rman target /

SWITCH DATAFILE '+DATA_BKP/orcl/datafile/' TO COPY;

step 5: Recover the datafile

RECOVER DATAFILE '+DATA_BKP/orcl/datafile/';

step 6: Bring the datafile online

ALTER DATABASE DATAFILE '+DATA_BKP/orcl/datafile/' ONLINE;