ExecuteSQL = "var v sys_refcursor; \n";
                ExecuteSQL = "BEGIN; \n";
                ExecuteSQL += "execute v :=calculateparentclassnodes_del3('77014000','GPC');";
                ExecuteSQL = "END;; \n";
                OracleCommand cmd = new OracleCommand(ExecuteSQL, con);
                DataSet ds = new DataSet();
                OracleDataAdapter da = new OracleDataAdapter(cmd);
                da.Fill(ds);

                ExecuteSQL = "DECLARE v sys_refcursor; \n";
                ExecuteSQL += "BEGIN \n";
                ExecuteSQL += "execute :v calculateparentclassnodes_del3('77014000','GPC'); \n";
                ExecuteSQL += "END; \n";

string ExecuteSQL= "Execute calculateparentclassnodes_del3('77014000','GPC');";
OracleCommand cmd = new OracleCommand(ExecuteSQL, con);
OracleDataAdapter da = new OracleDataAdapter(cmd);

con.Open();
string ExecuteSQL = String.Empty;
ExecuteSQL += " :cur_testes := calculateparentclassnodes_del3('77014000','GPC'); ";
OracleCommand cmd = new OracleCommand(ExecuteSQL, con);
cmd.Parameters.Add(new OracleParameter("cur_testes", OracleDbType.RefCursor,  ParameterDirection.ReturnValue);
DataSet ds = new DataSet();
OracleDataAdapter da = new OracleDataAdapter(cmd);

select calculateparentclassnodes_del3('77014000','GPC') from dual

{<PARENTCLASSCATEGORYCODE=77010000>,<PARENTCLASSCATEGORYCODE=77000000>,}

                ExecuteSQL = "select calculateparentclassnodes_del3('77014000','GPC') from dual; ";
                OracleCommand cmd = new OracleCommand(ExecuteSQL, con);
                DataSet ds = new DataSet();
                OracleDataAdapter da = new OracleDataAdapter(cmd);
                da.Fill(ds);

create or replace
PACKAGE Pkg_parentclasscatycode IS
 TYPE classparent_tbl IS TABLE OF classrelation.parentclasscategorycode%TYPE INDEX BY BINARY_INTEGER;
 FUNCTION calculateparentclassnodes_Cur ( iCode IN VARCHAR2,  iAgency IN VARCHAR2) return classparent_tbl;
END Pkg_parentclasscatycode;

create or replace
PACKAGE BODY Pkg_parentclasscatycode AS 
  FUNCTION  calculateparentclassnodes_Cur(
    iCode IN VARCHAR2,
		iAgency IN VARCHAR2)
    RETURN classparent_tbl
  AS 
  CURSOR cur_parentclasscatycode (in_iCode IN VARCHAR2, in_iAgency IN VARCHAR2 ) IS
    WITH parents  (parentclasscategorycode ) AS (SELECT parentclasscategorycode FROM classrelation WHERE childclasscategorycode=in_iCode 
        and classagencyname=in_iAgency 
    UNION ALL
        SELECT cl.parentclasscategorycode FROM classrelation cl, parents pa WHERE cl.childclasscategorycode = pa.parentclasscategorycode
            AND cl.classagencyname = in_iAgency)
    SELECT distinct parentclasscategorycode FROM parents;
    
    parentClassNodeCode_TabAux classparent_tbl;
    
  BEGIN
  IF NOT cur_parentclasscatycode%ISOPEN then
        OPEN cur_parentclasscatycode(iCode, iAgency);
  END IF;

  FETCH cur_parentclasscatycode bulk collect into parentClassNodeCode_TabAux;
  return parentClassNodeCode_TabAux;
  END calculateparentclassnodes_Cur;
END Pkg_parentclasscatycode;

 select Pkg_parentclasscatycode.calculateparentclassnodes_Cur('77014000','GPC') from dual 

 ORA-00902: tipo de dados inválido
00902. 00000 -  "invalid datatype"
*Cause:    
*Action:
Error at Line: 2 Column: 7 

SCOTT@orcl_11gR2> create table classrelation
  2    (parentclasscategorycode  varchar2 (23),
  3  	childclasscategorycode	 varchar2 (22),
  4  	classagencyname 	 varchar2 (15))
  5  /

Table created.

SCOTT@orcl_11gR2> insert into classrelation values
  2  ('77000000', '77010000', 'GPC')
  3  /

1 row created.

SCOTT@orcl_11gR2> insert into classrelation values
  2  ('77010000', '77014000', 'GPC')
  3  /

1 row created.

SCOTT@orcl_11gR2> insert into classrelation values
  2  ('77014000', '2', 'GPC')
  3  /

1 row created.

SCOTT@orcl_11gR2> create or replace type classparent_tbl as table of varchar2 (23);
  2  /

Type created.

SCOTT@orcl_11gR2> create or replace
  2  PACKAGE Pkg_parentclasscatycode IS
  3  -- TYPE classparent_tbl IS TABLE OF classrelation.parentclasscategorycode%TYPE INDEX BY BINARY_INTEGER;
  4   FUNCTION calculateparentclassnodes_Cur ( iCode IN VARCHAR2,  iAgency IN VARCHAR2) return classparent_tbl;
  5  END Pkg_parentclasscatycode;
  6  /

Package created.

SCOTT@orcl_11gR2> show errors
No errors.
SCOTT@orcl_11gR2> create or replace
  2  PACKAGE BODY Pkg_parentclasscatycode AS
  3    FUNCTION  calculateparentclassnodes_Cur(
  4  	 iCode IN VARCHAR2,
  5  		     iAgency IN VARCHAR2)
  6  	 RETURN classparent_tbl
  7    AS
  8    CURSOR cur_parentclasscatycode (in_iCode IN VARCHAR2, in_iAgency IN VARCHAR2 ) IS
  9  	 WITH parents  (parentclasscategorycode ) AS (SELECT parentclasscategorycode FROM classrelation WHERE childclasscategorycode=in_iCode
 10  	     and classagencyname=in_iAgency
 11  	 UNION ALL
 12  	     SELECT cl.parentclasscategorycode FROM classrelation cl, parents pa WHERE cl.childclasscategorycode = pa.parentclasscategorycode
 13  		 AND cl.classagencyname = in_iAgency)
 14  	 SELECT distinct parentclasscategorycode FROM parents;
 15  
 16  	 parentClassNodeCode_TabAux classparent_tbl;
 17  
 18    BEGIN
 19    IF NOT cur_parentclasscatycode%ISOPEN then
 20  	     OPEN cur_parentclasscatycode(iCode, iAgency);
 21    END IF;
 22  
 23    FETCH cur_parentclasscatycode bulk collect into parentClassNodeCode_TabAux;
 24    return parentClassNodeCode_TabAux;
 25    END calculateparentclassnodes_Cur;
 26  END Pkg_parentclasscatycode;
 27  /

Package body created.

SCOTT@orcl_11gR2> show errors
No errors.
SCOTT@orcl_11gR2> select Pkg_parentclasscatycode.calculateparentclassnodes_Cur('77014000','GPC')
  2  from   dual
  3  /

PKG_PARENTCLASSCATYCODE.CALCULATEPARENTCLASSNODES_CUR('77014000','GPC')
--------------------------------------------------------------------------------
CLASSPARENT_TBL('77010000', '77000000')

1 row selected.

SCOTT@orcl_11gR2> select *
  2  from   table
  3  	      (Pkg_parentclasscatycode.calculateparentclassnodes_Cur
  4  		 ('77014000','GPC'))
  5  /

COLUMN_VALUE
-----------------------
77010000
77000000

2 rows selected.

SCOTT@orcl_11gR2>

  CURSOR cur_parentclasscatycode (in_iCode IN VARCHAR2, in_iAgency IN VARCHAR2 ) IS
    WITH parents  (parentclasscategorycode ) AS (SELECT parentclasscategorycode FROM classrelation WHERE childclasscategorycode=in_iCode 
        and classagencyname=in_iAgency 
    UNION ALL
        SELECT cl.parentclasscategorycode FROM classrelation cl, parents pa WHERE cl.childclasscategorycode = pa.parentclasscategorycode
            AND cl.classagencyname = in_iAgency)
    SELECT distinct parentclasscategorycode FROM parents;

OPEN cur_testes FOR select parentclasscategorycode
from
  classrelation
  where
  classagencyname=iAgency
start with
  childclasscategorycode = iCode
connect by 
  prior parentclasscategorycode = childclasscategorycode;