How many numbers are the 6 being chosen from because that will decide for the probability.
For instance, if there are 50 likely numbers that can be drawn:
The first ball has a 6 in 50 probability of being one of your numbers. This is a 3/25 chance.
For the second, you have 1 less number and there are 49 numbers left. That's a 5/49 likelihood.
The remaining probabilities are 4/48 (or 1/12), 3/47, 2/46 (or 1/23), and 1/45.
As all of the numbers need to match, the probabilities multiply:
(3/25) * (5/49) * (1/12) * (3/47) * (1/23) * (1/45) = 1/15890700 will be the probability.