i found a solution but there is a small limitation, however it will work in 99% cases..
select top 1* from (
select * from [TableName] EXCEPT
select top (select (COUNT(1)-2) from [TableName]) * from [TableName]) A
Limitation : If last 2 rows/ second last row is duplicate of any row then it will give wrong result... but such cases are very rare in real scenarios.