SQL Statement With Varchar Datatype Size

The below table and functions are examples, but issue is like this.

i have one issue while forming below sql , Application will form this query at run time wih required inputs
it is failing because the application will not support the clob datatype.

Table : T_E (similar to EMP table structure)

This table has data similar to emp but bulk data around 10k records.

Query formed

select empno,ename, get_employees(deptno)
from t_e;

This sql query this is failing when function return varchar2 string more than 4000 size.Because in sql query size should not exceed 4000 for varchar2 data type , function return size can be upto 20000

Function which
CREATE OR REPLACE FUNCTION get_employees (p_deptno in emp.deptno%TYPE)
RETURN varchar2
IS
l_text varchar2(32767) := NULL;
BEGIN
FOR cur_rec IN (SELECT ename FROM t_e WHERE deptno = p_deptno) LOOP
l_text := l_text || ',' || cur_rec.ename;
END LOOP;
RETURN LTRIM(l_text, ',');
END;

I can try this with clob but application doesn't support that..so i tried with using clob in above function , after that while returning to application i want to conver the clob to char and return the entire string

select empno,ename, to_char(substring(get_employees(deptno),1,4000)) -- first 4000 characters
, to_char(substring(get_employees(deptno),4000,8000)) -- next 4000 characters
from t_e;

But this is failing how to return the entire string in above sql