You don't tell SQL what you don't want, you tell SQL what you DO want. So in your select, list out every column but EMP_NAME.
i found that there is no way to exclude a column name in a sql(Oracle 11g).
Correct - not in 11g nor any other version.
If such an 'exclusion' is needed on a routine basis then create a VIEW that only includes the specific columns of interest and grant SELECT privileges on that view to the users that need it. Then they can query the view and will NOT have access to those 'excluded' columns.