We can use below query to  find out the patch level of any product you have installed in e-Business Suite
Query:

sqlplus apps/

  SELECT substr(APPLICATION_SHORT_NAME,1,8) product,
substr(PRODUCT_VERSION,1,14) version,
substr(PATCH_LEVEL,1,11) patch_level
FROM fnd_application a, fnd_product_installations p
WHERE a.application_id = p.application_id
ORDER BY application_short_name;