Let us how to relocate tablespace in offline method  

S-1: To start the db in mount stage

sql> startup mount
ORACLE instance started.

Total System Global Area  167772160 bytes
Fixed Size                   787968 bytes
Variable Size              61864448 bytes
Database Buffers          104857600 bytes
Redo Buffers                 262144 bytes
Database mounted.

S-2: To take "B"  tablespace offline

SQL> alter tablespace B offline;

Tablespace altered.

S-3: View the location of that tablespace location

SQL> select file_name from dba_data_files where tablespace_name='B';

FILE_NAME
----------------------------
/u01/app/oracle/product/11.2.0.3/oradata/TEST/b.dbf

S-4: To relocate the tablespace using below code  

SQL> alter database rename file '/u01/app/oracle/product/11.2.0.3/oradata/b.dbf' to '/u02/test/b.dbf';

S-5; open the database and check  the file_name location in dba_data_files

SQL> alter database open;