Fetch data if exist in distinct of another column
I could achieve the result you expected with this query:

;WITH CTE (CompanyName, Total)
AS
(
    SELECT companyName, COUNT(1)
    FROM TestData
    GROUP BY CompanyName
)
SELECT TD.CompanyName, TD.TaxPaidOn, TD.OtherInfo
FROM CTE
    INNER JOIN TestData AS TD 
    ON CTE.CompanyName = TD.CompanyName
WHERE Total = (SELECT MAX(Total) FROM CTE)
ORDER BY TD.TaxPaidOn;


It doesn't have a DISTINCT though.