Thanks Nathan,
But in my case I am not using the WebRequest. I have a client server environment.
On server there is window service running on a port. and client side I am running another window application that creates a socket connection (Socket Programming) by calling Connect() method of class System.Net.Sockets.Sockets. So I want to secure this connection with SSL/TLS. I am using visual studio 2008 with .net 3.5 for crating the client application and window service. You can refer the below code how I am creating a connection between client and server.
clientSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
IPAddress remoteIp = IPAddress.Parse("Server IP");
int serverPort = Convert.ToInt32("Server Port");
IPEndPoint ipEnd = new IPEndPoint(remoteIp, serverPort);
clientSocket.Connect(ipEnd);