How to get Sql query for order by in respecive of Case Insensitive in Oracle

create table test (case varchar2(10));

Table created. 

 insert into test  values('a');

 insert into test  values('B');

 insert into test  values('c');
 insert into test  values('D');
 insert into test  values('E');
 insert into test  values('D'); 
 insert into test  values('D');

select * from test  

CASE

D
f
a
B
c
D
E
D
f   

 select * from test order by case 

CASE 

B
D
D
D
E
a
c
f
f 

select * from test order by order by nlssort(case,'NLS_SORT=BINARY_CI');

CASE       
----------
a          
B          
c          
D          
D          
D          
E          
f          
f          
 9 rows selected