after couple of hours i got my solution…thanks for your support..its works perfectly for me …
SELECT *
FROM table_name
WHERE STR_TO_DATE(created_datetime, ‘%d/%m/%Y’) BETWEEN DATE_SUB(CURDATE(), INTERVAL 15 DAY)
AND DATE_SUB(CURDATE(), INTERVAL 15 DAY)
solved How did fetch records inserted on exactly on 15th day before from current date in mysql [closed]