Rescheduling U.S. B1/B2 visa appointment in India – do I need to change both OFC and consular appointments together ?

I'm booking a U.S. B1/B2 visa appointment in India and I'm a bit confused about how the appointment system works.

If I book an OFC appointment first, but there are no good Consular interview dates available, what happens? Can I cancel the OFC selection and look again, or am I forced to take whatever Consular date is available?