Something

var
   Form1: TForm1;
   ButtonArray : array [0..10] of TButton;

implementation

{$R *.dfm}

Procedure Reordenar();
var  i, j, doing: Integer;
       exists: boolean;
begin
  doing:=0;

  repeat
    exists:=false;
    i:=random(9)+1;
    for j:=0 to doing do
       if ButtonArray[j].caption=IntToStr(i) then
       begin
          exists:=true;
          break;
       end;
    if exists=false then
    begin
       ButtonArray[doing].Caption:=IntToStr(i);
       inc(doing);
    end;
  until (doing=9) and (exists=true)
end;

procedure TForm1.FormCreate(Sender: TObject);
  var  i, j: Integer;
begin
   randomize;
   i:=0;
   for j := 0 to ComponentCount-1 do
      if (components[j].classtype = TButton) then
      begin
         ButtonArray[i] := TButton(Components[j]);
         inc(i);
      end;
   Reordenar();
end;

procedure TForm1.Button10Click(Sender: TObject);
begin
   reordenar();
end;