There are several possible answers depending on what you are asking about:
1. Anyone can make a reservation and dine at any restaurant in a park or resort. You don't need to be staying there to have a meal at one of the DW restaurants.
Or:
2. At 180 days before the day you want to eat anyone can make a reservation regardless of whether you're staying on property, offsite or are a local resident.
Or
3. If you want to take advantage of the 180 + 10 days then you have to be staying at one of the Disney owned resorts on property. Once you link your resort reservation, you'll be able to make reservations 180 days before your arrival for the arrival day and the first 10 days of your vacation.