try the below query
SELECT
max(T0.DocDate) as 'Date',
max(T1.CardName) as 'Vendor Name',
max(T0.Address) as 'Vendor Address',
count(T0.DocNum) as 'No. of Invoices',
COUNT(T5.DocNum) AS 'No of Credit Memos',
max(T1.LicTradNum) as 'TIN No.',
sum(T0.BaseAmnt) as 'Base Amount',
sum(T0.VatSum) as 'Input Tax',
max(T1.ECVatGroup ) as 'TaxCode',
max(T2.WTCode) as 'WtaxCode'
FROM OPCH T0 INNER JOIN OCRD T1 ON T0.CardCode = T1.CardCode
INNER JOIN pch1 t3 ON t3.DocEntry=t0.DocEntry
LEFT JOIN dbo.RPC1 T4 ON T4.BaseEntry=T3.DocEntry left JOIN dbo.ORPC T5 ON T5.DocEntry=T4.DocEntry
left join PCH5 T2 on T0.DocEntry = T2.AbsEntry
WHERE T0.DocDate BETWEEN '[%0]' and '[%1]' and T0.VatSum <> 0
GROUP BY T1.CardCode
--Manish