oracle tablespace character set
The character set of an Oracle database is set at the database level, not tablespace level.

You have 3 options:


Recreate the database with the correct character set 
Convert the database to AL32UTF8. Documentation link
Change the databases National Character Set to AL32UTF8 &amp; change your application to use
NVARCHAR2()/NCHAR() datatypes instead of VARCHAR2() (documented at the same link as above)