Using RFID RDM6300

Hello Everyone.
I have some trouble when i using RFID RDM6300.
I only read the TAG. this is the simple program i get from

#include <SoftwareSerial.h>
SoftwareSerial RFID(2, 3); // RX and TX

int i;

void setup()
{
RFID.begin(9600); // start serial to RFID reader
Serial.begin(9600); // start serial to PC
}

void loop()
{
if (RFID.available() > 0)
{
i = RFID.read();
Serial.print(i, DEC);
Serial.print(" ");
}
}

When i using arduino UNO this program running and no problem.'

But when i using arduino Mega2560 the program Cannot running.

Help me please.
Thank you

Why would you use SoftwareSerial on a Mega when it has 3 spare HardwareSerial ports?

You have not told us what actually happens when you try the program on the Mega.

Please modify your post and use the code button </> so your code looks like this and is easy to copy to a text editor. See How to use the Forum

...R