The rule for this is n/6. I will help prove this with what we have and then continue until the 7th term.
12/6 = 2
2/6 = 1/3
1/3 / 6 = 1/18
1/18 / 6 = 1/108
1/108 / 6 = 1/648
1/648 / 6 = 1/3888
1/3888 / 6 = 1/23328
Your 7th term is 23328.
A quick way to find the answer to dividing a fraction by a whole number, is to multiply the denominator by the whole number and put that as 1/x ( being the product).
I hope this helps!