Uri address = new Uri("https://api.vk.com/blablabla");
ServicePointManager.ServerCertificateValidationCallback = delegate { return true; };
ServicePointManager.SecurityProtocol = SecurityProtocolType.Ssl3 | SecurityProtocolType.Tls | (SecurityProtocolType)(0xc0 | 0x300 | 0xc00);
WebClient client = new WebClient();
client.Encoding = System.Text.Encoding.UTF8;
String request = client.DownloadString(address);
client.Dispose();
YourObject myobject = JsonParser.deserialize(request);//так как C# не имеет встроенных методов разборки JSON то тут вызрв библиотечной функции.