How to read data from xml file and display it over the text box in delphi language

Have a look at Delphi's own TXMLDocument component, for example:

uses
  ..., XMLIntf, XMLDoc;

procedure TForm1.FormCreate(Sender: TObject);
var
  Vehicle: IXMLNode;
begin
  XMLDocument1.FileName :='vehicle.xml';
  XMLDocument1.Active := True;
  try
    Vehicle := XMLDocument.DocumentElement;
    txtType.Text := Vehicle.ChildNodes['type'].Text;
    txtModel.Text := Vehicle.ChildNodes['model'].Text;
    txtnumber.Text  := Vehicle.ChildNodes['number'].Text;
  finally
    XMLDocument1.Active := False;
  end;
end;

Alternatively, use the IXMLDocument interface directly (which TXMLDocument implements):

uses
  ..., XMLIntf, XMLDoc;

procedure TForm1.FormCreate(Sender: TObject);
var
  Doc: IXMLDocument;
  Vehicle: IXMLNode;
begin
  Doc := LoadXMLDocument('vehicle.xml');
  Vehicle := Doc.DocumentElement;
  txtType.Text := Vehicle.ChildNodes['type'].Text;
  txtModel.Text := Vehicle.ChildNodes['model'].Text;
  txtnumber.Text := Vehicle.ChildNodes['number'].Text;
end;

---

Update: the XML in the question has been altered to now wrap the vehicle element inside of a data element, and to have multiple vehicle elements. So the code above has to be adjusted accordingly, eg:

uses
  ..., XMLIntf, XMLDoc;

procedure TForm1.FormCreate(Sender: TObject);
var
  Doc: IXMLDocument;
  Data: IXMLNode;
  Node: IXMLNode;
  I: Integer;
begin
  Doc := LoadXMLDocument('vehicle.xml');
  Data := Doc.DocumentElement;
  for I := 0 to Data.ChildNodes.Count-1 do
  begin
    Node := Data.ChildNodes[I];
    // if all of the child nodes will always be 'vehicle' only
    // then this check can be removed...
    if Node.LocalName = 'vehicle' then
    begin
      // use Node.ChildNodes['type'], Node.ChildNodes['model'],
      // and Node.ChildNodes['number'] as needed...
    end;
  end;
end;

You can read the XML file using the unit MSXML (or any other XML parser).

It gives you a tree structure representing the XML file. Where vehicle is the top node and the other three are the child nodes.

Each node has a text property that can be used to get the value. You can assign that to the text boxes on your form.

Code sample:

uses
  ActiveX,
  MSXML;

procedure TForm1.ReadFromXML(const AFilename: string);
var
  doc : IXMLDOMDocument;
  node : IXMLDomNode;

begin
  CoInitialize; // Needs to be called once before using CoDOMDocument.Create;
  if not FileExists(AFileName) then 
    Exit; // Add proper Error handling.

  doc := CoDOMDocument.Create;
  doc.load(AFileName);

  if (doc.documentElement = nil) or (doc.documentElement.nodeName <> 'vehicle') then
    Exit; // Add proper Error handling.

  node := doc.documentElement.firstChild;
  while node<>nil do begin
    if node.nodeName = 'model' then
      txtModel.Text := node.text;
    if node.nodeName = 'number' then
      txtNumber.Text := node.text;
    if node.nodeName = 'type' then
      txtType.Text := node.text;
    node := node.nextSibling;
  end;
end;