You have to find an equivalent denominator. The two fractions are 1/12 and 6/8. I'll show you some work.
6/8 ; 12/16 ; 18/24
1/12 ; 2/24
Now that we know the denominator is 24, we can simplify 18/24.
18/24 ; 9/12
Your answer should be 9/12. Hope this helps! :)