DecimalSeparator in SysUtils and System.SysUtils

My bad, first I needed to call FormatSettings, and then I can use in DecimalSeparator in Delphi XE6,

FormatSettings.DecimalSeparator

procedure ConfigureBrazilRegion;
var
  FormatBr: TFormatSettings;
begin
  // Create new setting and configure for the brazillian format
  FormatBr                     := TFormatSettings.Create;
  FormatBr.DecimalSeparator    := ',';
  FormatBr.ThousandSeparator   := '.';
  FormatBr.CurrencyDecimals    := 2;
  FormatBr.DateSeparator       := '/';
  FormatBr.ShortDateFormat     := 'dd/mm/yyyy';
  FormatBr.LongDateFormat      := 'dd/mm/yyyy';
  FormatBr.TimeSeparator       := ':';
  FormatBr.TimeAMString        := 'AM';
  FormatBr.TimePMString        := 'PM';
  FormatBr.ShortTimeFormat     := 'hh:nn';
  FormatBr.LongTimeFormat      := 'hh:nn:ss';
  FormatBr.CurrencyString      := 'R$';

  // Assign the App region settings to the newly created format
  System.SysUtils.FormatSettings := WFormatBr;
end;