There are two ways :
Either you have to write another query in your stored-procedure (if you are using)which will return you total record column and then you can use Dataset to display records from two tables.
or
try this if you want to do it into one query
SELECT
TotalRecords = COUNT(*) OVER(),
tblTaxingSchemeDetails.TaxSchemeDetailsId,
tblTaxingScheme.TaxSchemeId,
tblTaxingScheme.TaxSchemeName,
tblTaxingSchemeDetails.TaxType,
TaxName,
tblTaxingSchemeDetails.TaxRate
From tblTaxingScheme INNER JOIN tblTaxingSchemeDetails
On tblTaxingScheme.TaxSchemeId = tblTaxingSchemeDetails.TaxSchemeId
INNER JOIN tblTaxType
on tblTaxingSchemeDetails.TaxType = tblTaxType.TaxTypeID
where tblTaxingScheme.TaxSchemeId =@TaxSchemeId
Thanks