Thanks for all ur answers and time :)
well I figured out where I went wrong thanks to oracle sql developer actually something wrong with for loop
here is code (corrected code for loop)
OPEN projMgrsCursor;
LOOP
FETCH projMgrsCursor INTO projMgrs;
EXIT WHEN projMgrsCursor%NOTFOUND;
insert into
MICL_SUPERVISORS VALUES ((:NEW.ID), (SELECT SYSDATE FROM DUAL), :NEW.ENTRYADDEDBY_EMP_NO, 3000, 0,projMgrs, NULL,:NEW.EMP_NO);
END LOOP;
CLOSE projMgrsCursor;
Hope that this will help to anyone like me :)