Use SUBSTR instead of SUBSTRING.
Using the same example from above.
For example:
SELECT * FROM JOBS JS
INNER JOIN EMPLOYEES EMP ON JS.JOB_ID = EMP.JOB_ID AND MIN_SALARY = 4200
WHERE JS.JOB_ID = 'AC_ACCOUNT'
AND SUBSTR(TRIM(NVL(JS.JOB_TITLE,'')),14,1) IN ('T');
