You can safely keep a fresh turkey in the freezer 6 months to a year before cooking the turkey.
However if you keep the fresh turkey inside the refrigerator before cooking it then you can safely keep the fresh thawed out turkey in the refrigerator for up to 3 days before cooking it.
What I do is remove the turkey from the freezer a 2 days before cooking the turkey and put the turkey in the refrigerator for those 2 days.
Those 2 days in the refrigerator allows the turkey to thaw out enough to cook but keeps the turkey cold enough to avoid spoilage due to bacteria that could grow on the turkey if it wasn't kept cold enough.
As long as you cook the fresh turkey within 3 days of it being kept refrigerated then it will be safe and good to eat but if you want to keep the fresh turkey longer than 3 days before cooking it you should freeze the turkey so it can last 6 months to a year.