what i have wrong in this code as always the same led is going on
Several things. You should be generating two random numbers - one for the pin and one for the state - not three.
int randPin = random(11, 14); // Generate value from 11 to 13
int randState = random(0, 2); // Generate value from 0 to 1
digitalWrite(randPin, randState); // Set the pin to the state
Seeding the random number generator would be useful, too.