Adding Discounts

[priyanka]

Hi,
I want to add discount for my subscription product.
Allow discount a subscription based on if they pay in advance for more months, ie: user picks Level1 $10, then option to recur monthly, or pre-pay for 3 months and save 15% and recur payment every 3 months, or pre-pay for 6 months and save 25% and recur payment every 6 months.

How can i add these discount levels to subscription?

[plugables]

This is something that can't be achieved without customization.