OK - 300 carb grams is the recommended daily intake for "normal diets". You can check this on
www.fitday.com.
Atkins limits carbs to 20 per day during the 2-week induction perios. CAD and CALP want carbs at 2 meals kept very low - like 5 per meal but allow unlimited carbs at the 3rd meal AS LONG AS equal amounts of protein, carbs and veggies are eaten within a one-hour time period.
On WW Lower Carb, I allow myself about 100 carbs a day but don't agonize over it!
My very best advice is to borrow the low carb books from the Library or research on the net before chosing a plan.
Good luck but rely on knowledge and planning.