Getting ORA-06502 error..Pls Help

[ales]

There could be also Com_Id overflow or type mismatch.
Declare Com_Id as RPTDEFN.NAME_ID%TYPE, not NUMBER(10).

I'd suggest to write an exception block and write all the variables out.

...
EXCEPTION
  WHEN OTHERS THEN
    dbms_output.put_line(length(Com_list));
    dbms_output.put_line(Com_list);
    dbms_output.put_line(CompId)
...

Feel free to post further questions.
Ales