<report>
  
      <task_stats>
        <info_group name="task_info">
          <info name="status">ZZZZZZZ</info>
        </info_group>
      </task_stats>

</report>

 
DECLARE
 key_enable    varchar2(20);
 rept          varchar2(4000)
......
 -- rept get xml data from other process 
 -- rept= dbms_report.get_report(pre_rept);
 -- I tried extract and extractValue as below

   BEGIN
select XMLType(rept).extractValue('/info') into key_enable from dual;


select XMLType(rept).extract('/info') into key_enable from dual;

  END 

SQL> with data as (
  2    select xmltype('<report>
  3  <task_stats>
  4  <info_group name="task_info">
  5  <info name="status">ZZZZZZZ</info>
  6  </info_group>
  7  </task_stats>
  8  </report>') d from dual
  9    )
 10  select extractvalue(d,'/report/task_stats/info_group/info') val
 11  from data
 12  /
VAL
----------------------------------------------------------------
ZZZZZZZ

1 row selected.

DECLARE
  rept          varchar2(4000);
  rept_xml      varchar2(4000);
  rref          varchar2(4000);
  key_enable    varchar2(20);

BEGIN
 ---other prceure to get rref rref := dbms_report.build_report_reference_varg('xxxxx') ;

 rept := dbms_report.get_report(rref);
 dbms_output.put_line('rept is ' || rept);
  -- rept  output as above sample

  with data as ( select xmltype(rept) rept_xml from dual)

--  select extractvalue(rept_xml,  '/report/task_stats/info_group/info') val from dual;
  select extractvalue(rept_xml,  '/report/task_stats/info_group/info') into key_enable from dual;
  select extractvalue(rept_xml,  '/report/task_stats/info_group/info').getstringval() into key_enable from dual;


 dbms_output.put_line( 'key_enable is ' || key_enable);
                  
END

SQL> DECLARE
  2    rept          varchar2(4000);
  3    rept_xml      varchar2(4000);
  4    rref          varchar2(4000);
  5    key_enable    varchar2(20);
  6  
  7  BEGIN
  8  
  9   -- rept := dbms_report.get_report(rref);
 10   rept := '<report>
 11    
 12        <task_stats>
 13          <info_group name="task_info">
 14            <info name="status">ZZZZZZZ</info>
 15          </info_group>
 16        </task_stats>
 17  
 18  </report>';
 19   dbms_output.put_line('rept is ' || rept);
 20    -- rept  output as above sample
 21  
 22    with data as ( select xmltype(rept) rept_xml from dual)
 23    select extractvalue(rept_xml,  '/report/task_stats/info_group/info') 
 24      into key_enable from data; -- not dual
 25  
 26   dbms_output.put_line( 'key_enable is ' || key_enable);
 27                    
 28  END;
 29  /
rept is <report>

      <task_stats>
        <info_group name="task_info">
          <info name="status">ZZZZZZZ</info>

        </info_group>
      </task_stats>

</report>
key_enable is ZZZZZZZ

PL/SQL procedure successfully completed.