NEET contains 180 questions (45 questions each from Physics and Chemistry and 90 questions from Biology). Each correct response to a question will get you 4 marks; and each wrong response will get 1 mark deducted. So, the maximum marks is 720 marks.
Generally, to get a government college, you should score above 500-520. To get good colleges, 550+ is good. If you want the top ranking colleges, look at 600+. These marks are general guidance and could change depending on the difficulty level of the exam in a particular year.