How to take minimum id rows take in Sql server 2008 r2

If you want a single row to return then you can do it alternatively using TOP clause.

SELECT TOP 1 Id, item_code, item_name, item_price, StockInHand, actv_code, actv_name 
FROM Stocks 
ORDER BY Id

If you want minimum id with same item_code then you can try something like-

SELECT S.Id, S.item_code, item_name, item_price, StockInHand, actv_code, actv_name 
FROM Stocks S
INNER JOIN 
(
  SELECT MIN(Id), item_code   
  FROM Stocks 
  GROUP BY item_code
) AS T
ON S.Id=T.Id

If you want something else than this, please let me know.

Hope, it helps :)