"How do I find Nth maximum value?" is one of the most asked questions
Here are some methods 

I explain how to find 5th Maximum value

declare  @number table(num integer)  

Insert into @number values(3456)
Insert into @number values(846)
Insert into @number values(1456)
Insert into @number values(3098)
Insert into @number values(34)
Insert into @number values(67856)
Insert into @number values(906)
Insert into @number values(34656)
Insert into @number values(9056)
Insert into @number values(3036) 

(1) Use Inner Join

select t1.num from @number t1 inner join @number t2 on t1.num<=t2.num
group by t1.num having count(t1.num)=5

(2) Use Top Operator

Select top 1 num from
(
        Select top 5 num from @number order by num desc
) T
order by num asc

(3) Generate Serial No based on descending order of the

select num from
( 
        Select (select count(*) from @number where num>=T.num)as Sno ,num 
        from @number as T
) as temp
where Sno=5

(4) Generate Serial No based on descending order of the values in where Clause

select num from @number as n
where (select count(*) from @number where num>=n.num)=5 

(5) Use Aggregate

Select min(num) from (select top 5 num from @number order by num desc) T 

(6) Use Row_number() function

select num from
(
        select num, row_number() over (order by num desc) as sno from @number
) as t
where sno=5 

Now you can replace 5 to the number that you want to find the maximum value