create or replace package Package1 is
cursor cl is 
select s.sample_id, p.mplate_id from XXXX.mwell w,
XXXX.mplate p, XXXX.sample s where
p.mplate_code=w.mplate_code and w.sample_code=s.sample_code;

type TermsCur is ref cursor return cl%rowtype;
vSql VARCHAR2(2000);
vQueryHandle INTEGER;
vErrorCode INTEGER;

procedure Procedure1(PlateIDs_in IN VARCHAR2,Termset IN OUT TermsCur);
end Package1; 
/

create or replace package body Package1 is

procedure Procedure1
(PlateIDs_in IN VARCHAR2,
Termset IN OUT TermsCur) is

begin
open Termset for 
select s.sample_id, p.mplate_id from XXXX.mwell w,
XXXX.mplate p, XXXX.sample s where
p.mplate_id=PlateIDs_in and 
p.mplate_code=w.mplate_code and w.sample_code=s.sample_code;
end Procedure1;

end Package1;
/
SHOW ERRORS