If you need more rate plans for example a non-refundable you can add these in your Booking.com extranet.
Policies
Add your cancelation policies in SETTINGS-CHANNEL MANAGER-BOOKING.COM-SPECIFIC ROOM CONTENT in "Custom".
General cancellation policies are set like this:
You can have cancellation policies per offer. Offer specific cancellation policies set like this:
These policies get linked to rate plans.
Fees
Star Rating (hotels only)
Meals