A certain hand

Hi guys what's the probability of hitting a queen on the turn when having queen 6

Not good enough to call a bet on the flip to find out

6.4%

You can calculate odds by dividing the amount of cards that help you by the amount of cards left in the deck.
3 queens in the deck/47 cards left in the deck=6.4%.
However, you probably shouldn't be seeing a flop with Q6, and definitely don't think about calling a bet if you don't hit the flop.

if this 3 players at the table, and I have a Q6. The probability that it will be Q = 3/45 Right?

No, because you don't know your opponents cards. You only see your 2 hole cards+3 cards on the flop. All the other cards are assumed to be still in the deck.