Hi Mohammadmk,
Check this example. Now please take its reference and correct your code.
HTML
<div class="lead" id="MyDiv" runat="server">
<p>
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</p>
<div class="lead" style="direction: rtl;">
<p>
لاوروف: آخرین ذره اعتمادمان به غرب را هم داریم از دست میدهیم</p>
</div>
</div>
<asp:Button ID="btnConvert" Text="Convert" runat="server" OnClick="btnConvert_Click" />
Namespaces
C#
using System.IO;
using iTextSharp.text;
using iTextSharp.text.html.simpleparser;
using iTextSharp.text.pdf;
using System.Text;
VB.Net
Imports System.IO
Imports iTextSharp.text
Imports iTextSharp.text.html.simpleparser
Imports iTextSharp.text.pdf
Imports System.Text
Code
C#
protected void btnConvert_Click(object sender, EventArgs e)
{
string strHtml = string.Empty;
string pdfFileName = Server.MapPath("~/files/div.pdf");
StringWriter sw = new StringWriter();
HtmlTextWriter hw = new HtmlTextWriter(sw);
MyDiv.RenderControl(hw);
StringReader sr = new StringReader(sw.ToString());
strHtml = sr.ReadToEnd();
sr.Close();
CreatePDFFromHTMLFile("<div style='font-family:arial unicode ms;'>" + strHtml + "</div>", pdfFileName);
Response.ContentType = "application/pdf";
Response.AddHeader("Content-Disposition", string.Format("attachment; filename=\"{0}\"", "div.pdf"));
Response.ContentEncoding = Encoding.UTF8;
Response.WriteFile(pdfFileName);
Response.HeaderEncoding = Encoding.UTF8;
Response.Flush();
Response.End();
}
private void CreatePDFFromHTMLFile(string html, string FileName)
{
TextReader reader = new StringReader(html);
Document document = new Document(PageSize.A4, 30, 30, 30, 30);
PdfWriter writer = PdfWriter.GetInstance(document, new FileStream(FileName, FileMode.Create));
HTMLWorker worker = new HTMLWorker(document);
document.Open();
FontFactory.Register("C:\\Windows\\Fonts\\ARIALUNI.TTF", "arial unicode ms");
iTextSharp.text.html.simpleparser.StyleSheet ST = new iTextSharp.text.html.simpleparser.StyleSheet();
ST.LoadTagStyle("body", "encoding", "Identity-H");
worker.SetStyleSheet(ST);
worker.StartDocument();
worker.Parse(reader);
worker.EndDocument();
worker.Close();
document.Close();
}
VB.Net
Protected Sub btnConvert_Click(ByVal sender As Object, ByVal e As EventArgs)
Dim strHtml As String = String.Empty
Dim pdfFileName As String = Server.MapPath("~/files/div.pdf")
Dim sw As StringWriter = New StringWriter()
Dim hw As HtmlTextWriter = New HtmlTextWriter(sw)
MyDiv.RenderControl(hw)
Dim sr As StringReader = New StringReader(sw.ToString())
strHtml = sr.ReadToEnd()
sr.Close()
CreatePDFFromHTMLFile("<div style='font-family:arial unicode ms;'>" & strHtml & "</div>", pdfFileName)
Response.ContentType = "application/pdf"
Response.AddHeader("Content-Disposition", String.Format("attachment; filename=""{0}""", "div.pdf"))
Response.ContentEncoding = Encoding.UTF8
Response.WriteFile(pdfFileName)
Response.HeaderEncoding = Encoding.UTF8
Response.Flush()
Response.[End]()
End Sub
Private Sub CreatePDFFromHTMLFile(ByVal html As String, ByVal FileName As String)
Dim reader As TextReader = New StringReader(html)
Dim document As Document = New Document(PageSize.A4, 30, 30, 30, 30)
Dim writer As PdfWriter = PdfWriter.GetInstance(document, New FileStream(FileName, FileMode.Create))
Dim worker As HTMLWorker = New HTMLWorker(document)
document.Open()
FontFactory.Register("C:\Windows\Fonts\ARIALUNI.TTF", "arial unicode ms")
Dim ST As iTextSharp.text.html.simpleparser.StyleSheet = New iTextSharp.text.html.simpleparser.StyleSheet()
ST.LoadTagStyle("body", "encoding", "Identity-H")
worker.SetStyleSheet(ST)
worker.StartDocument()
worker.Parse(reader)
worker.EndDocument()
worker.Close()
document.Close()
End Sub
Screenshot

Refering below link i have created the example.
https://stackoverflow.com/questions/10329863/display-unicode-characters-in-converting-html-to-pdf