PaulS i think that what the op wanted to do is to let a led light up in random which could me one of 2 which is red or blue, so when the red led light up, one of the rfid will turn the led off while the will not.
Probably. But, does that code correctly read the RFID tag? Does it correctly compare the tag read to the other two tags? What problem are we trying to solve?
If all that need to change is what action happens when tag 1 or tag 2 is scanned, then that is a trivial change. If collecting the data from the RFID is not working correctly, then the changes needed to the code are far more extensive. Where do we need to start?