Try to use query like this::
SELECT BatchNo, Medicine, SaleQty, TotalPrice, Batch_Qty, PurchaseRate, SaleRate, (A + B + C + N) AS Total, Now() AS [CurrentTime]
FROM(
SELECT CounterSale.Pro_Batch AS BatchNo, CounterSale.Pro_name As Medicine, Sum(CounterSale.cun_qty) AS SaleQty, Sum(CounterSale.cun_totalAmt) AS TotalPrice, PurchaseBatch.Bth_qty As Batch_Qty, PurchaseBatch.Bth_Pur_rate As PurchaseRate, PurchaseBatch.Bth_sale_rate As SaleRate
FROM SaleVouchers INNER JOIN (PurchaseBatch RIGHT JOIN CounterSale ON PurchaseBatch.Batch_no = CounterSale.Pro_Batch) ON SaleVouchers.Sal_voucher = CounterSale.Sal_voucher
WHERE sal_voucher_date between @RechargeDateStart AND @RechargeDateEnd GROUP BY CounterSale.Pro_Batch, CounterSale.Pro_name, PurchaseBatch.Bth_qty, PurchaseBatch.Bth_Pur_rate, PurchaseBatch.Bth_sale_rate)