In this paper, the authors analyse RFID technology, different types of Tags, Readers and various protocols associated with RFID. We read, write and dump the raw bytes from the MIFARE Classic Card using RC5220 and Arduino Mega.  Delhi Metro Card uses MIFARE DESFire. MIFARE DESFire uses 3(DES) for encryption. In this paper, we also read the data structure of the Delhi Metro Card. Additionally, we also compare MIFARE Classic Card and MIFARE DESFire Card.