All what you need to do is to
UNPIVOT[
^] data. Have a look at example:
DECLARE @emp TABLE (E_Name VARCHAR(30), Jan INT, Feb INT, March INT, Apr INT, May INT)
INSERT INTO @emp (E_Name, Jan, Feb, March, Apr, May)
VALUES('Amit', null, null, null, null, 25000),
('Sharad', 2000, null, null, null, null),
('Rohit', null, 1000, null, null, null),
('Kishor', null, null, 50000, null, null),
('Rahul', null, null, null, 6000, null)
SELECT Emp_Name, Month_Name, Salary
FROM (
SELECT E_Name AS Emp_Name, Jan, Feb, March, Apr, May
FROM @emp
) AS pvt
UNPIVOT (Salary FOR Month_Name IN ([Jan], [Feb], [March], [Apr], [May])) AS unpvt
Result:
Amit May 25000
Sharad Jan 2000
Rohit Feb 1000
Kishor March 50000
Rahul Apr 6000