"TypeError: 'tuple' object is not callable" error in Python while trying to get a object in tuple by indexing

I am getting this error "TypeError: 'tuple' object is not callable" whenever I am trying to get a object in tuple. My code is -

import random
import sys

inp = input("Press ENTER to start.")
sys.stdout.write("Rules --\nIn this game, you will have to correctly guess the word. If you can do that successfully, YOU WIN!\n")
sys.stdout.write("You will given (number of letters of the word + 2) chance. In each chance you will have to guess a letter of the word\n")
sys.stdout.write("If you run out of chance, you lose. :(\n")

while True:
    inp = input("Ready(Y/N)? ")
    if 'Y' in inp or 'y' in inp:
        print("Okay")
        break
    elif 'n' in inp or 'N' in inp:
        sys.exit

Word_List = ('banana', 'cat', 'mat', 'apple', 'pineapple', 'mango')
m = random.randint(1, 6)
word = Word_List(m)
chances = len(word) + 2

for x in range(len(word)):
    sys.stdout.write('_ ')

Can anyone spot the error?