How to make random with 2 numbers duplicate?

Can you help me to make a function random range 0-15 with 2 number duplicate? eg: i have 6 players: A,B,C,D,E,F. random player A and B or C or D or E or F will get same random range 0-15. then we get A = 1, C = 1 or B = 4, F = 4 or E = 14, B = 14

thanks in advance for your help