How to find particular cell values in sql

It would have helped if you had described what that value represents in terms of this data but your reference to

sic:

this type of any function is there in SQL or ACCESS or MYSQL

leads me to think of mathematical functions[^]

Of the data shown

Average = 18
Median = 20 
There is no mode

However the range is 15 so this query will get the results you want:

select max(age) - min(age) as ageRange from Table1

[EDIT]
My somewhat sarcastic solution above didn't go down so well. However, despite what other members are saying it is possible to filter the table without using WHERE. The real point is that you really shouldn't do it this way! (And I really do mean really).
It can be achieved using a CURSOR[^] and an IF[^] statement. For example:

declare @AgeToCheck int = 15
declare @ResultFound int = 0

declare @name varchar(125)
declare @age int
declare @address varchar(125)
declare @city varchar(125)
declare @state varchar(125)

DECLARE @ACursor CURSOR 
SET @ACursor = CURSOR FOR
	SELECT [name], age,[address], city,[state]
	FROM Table1

OPEN @ACursor
FETCH NEXT FROM @ACursor INTO @name, @age, @address, @city, @state
WHILE @@FETCH_STATUS = 0
BEGIN

	IF @age = @AgeToCheck
	BEGIN
		SET @ResultFound = 1
		BREAK
	END
	FETCH NEXT FROM @ACursor INTO @name, @age, @address, @city, @state
END
CLOSE @ACursor
DEALLOCATE @ACursor
select @name,@age,@address,@city,@state

Now doesn't that look horrible compared to

SELECT [name], age,[address], city,[state]
	FROM Table1
	WHERE age = @AgeToCheck

I cannot stress strongly enough that, just because something is possible does not mean that it is a sensible solution. Do not filter tables using Cursors.