How to apply pivot for this in SQL query

The link provided in Solution 1 is a good resource but I suspect you will need a little more help.

You don't appear to have any ID column for this table - the table is not fully normalised as you are duplicating data (Studentname) in each row, so StudendID doesn't count as the ID for the table.

That's not a problem until you want to understand in what order the marks were received. An identity column on your table will allow you to ORDER BY the order in which the rows were added to the table. A datetime column that is automatically updated would do the same, but the identity column is much easier - e.g.

create table students
(
    id int identity(1,1),
	StudendID int,
	Studentname varchar(30),
	StudentMark int
)

You will need to know the rank or number of each mark in relation to each student (assuming this table will have more than one student in it) in order to get the correct columns in your results.

To demonstrate what I mean I inserted this data in to the table

insert into students values
(17, 'raja',  105), (17, 'raja', 80), (17, 'raja',  90),
(18, 'malik', 85), (18, 'malik', 95),
(19, 'sanoop',75), (19, 'sanoop',85)

then ran this query

select StudendID, Studentname, StudentMark, 
   ROW_NUMBER() OVER (PARTITION BY StudendID ORDER BY id) AS rn
from students

which gives me these results

StudendID Studentname   StudentMark rn
17	  raja	        105	    1
17	  raja	        80	    2
17	  raja	        90	    3
18	  malik	        85	    1
18	  malik	        95	    2
19	  sanoop	75	    1
19	  sanoop	85	    2

So we can quite clearly see that raja's first mark was 105, his 2nd was 80 and his 3rd was 90.

If we stick that query into the simple pivot example on the link in Solution 1 we get this

select StudendID, Studentname, ISNULL([1],0) StudentMark_1, ISNULL([2],0) StudentMark_2, ISNULL([3],0) StudentMark_3
from
(
	select StudendID, Studentname, StudentMark, 
        ROW_NUMBER() OVER (PARTITION BY StudendID ORDER BY id) AS rn
	from students
) as query
PIVOT 
(
	MAX(StudentMark) FOR rn IN ([1],[2],[3])
) as pvt
order by StudendID

with these results

StudendID  Studentname  StudentMark_1 StudentMark_2 StudentMark_3
17	   raja	        105	      80	    90
18	   malik	85	      95	    0
19	   sanoop	75	      85	    0

The only other things worth noting are

- I used MAX(Studentmark) to get the marks into the PIVOT results because a summary function must be used in PIVOT. I could just have easily used SUM or AVG etc because there is only 1 value per student for each value of rn, but if no function is used then an error is thrown.

- I had to surround the 1,2,3 values with square brackets ([1],[2],[3]) in the PIVOT because they represent column names there, not values, and column names cannot start with a numeric.

- I used ISNULL() to tidy up the NULL values in my results for StudentMark_3 for malik and sanoop.