What specifies the salary amount? Based on what you have tried, there is some criteria to what defines the various types of salary base points.
If I had to guess, you are getting some syntax errors?
Have you tried
SELECT
MIN(details_Credit) as Salary_Amount_1,
MAX(details_Credit) as Salary_Amount_2,
CASE
WHEN details_Credit < MIN(details_Credit) and details_Credit > MIN(details_Credit) THEN
details_Credit
ELSE
NULL
END Salary_Amount_3,
NULL as Salary_Amount_4,
FROM table;