For every 1 cup of banana you have to add 6 cups of apples. So it means there's six times as much apples as there is bananas. If there's 3 cups of apples, which is half of 6, it means the banana would now also have to be halved from 1 to half a cup.
Whatever you do to the bananas or the apples, you have to maintain the same ratio. Which is that apples is 6 times as much as bananas.
So 1 cup of apple would need to be divided by 6, to get banana. That would be approximately 1÷6= 0.167 cups
