let originally numerator is x and denominator is y
So original fraction =
Now according to question
x = y-6 -----------------(1)
and
multiplying equation (1) with 3
we get
3x=3y-18....(3)
Now equation (3)-(2)
-9=y-18
So y=9
So x=y-6=9-6=3
So the fraction =