Hi SravanKN,
Please check with the below code. If Port "COM1" doesn't exist then uncomment the commented line.
SerialPort sp = new SerialPort();
//sp.PortName = "COM2";
sp.Open();
int length = sp.BytesToRead;
byte[] buf = new byte[length];
sp.Read(buf, 0, length);
System.Diagnostics.Debug.WriteLine("Received Data:" + buf);
Refer the below link.
http://stackoverflow.com/questions/21548828/c-sharp-serial-port-reading-hex-data