SQL> CREATE OR REPLACE package pack1 is 
  2  TYPE ref1 is ref cursor; 
  3  end; 
  4  / 

Package created.

SQL> CREATE OR REPLACE procedure proc1 (a IN number, b IN OUT pack1.ref1) is 
  2  begin 
  3  open b for select * from emp where empno = a; 
  4  end; 
  5  /

Procedure created.

SQL>  var r refcursor ;
SQL> exec proc1(7788,:r);

PL/SQL procedure successfully completed.

SQL> print r;

     EMPNO ENAME      JOB              MGR HIREDATE         SAL       COMM     DEPTNO
---------- ---------- --------- ---------- --------- ---------- ---------- ----------
      7788 SCOTT      ANALYST         7566 19-APR-87       3000                    20

1 row selected.