Hello Ambika ,In most states, with 400 + you can get a government medical seat. Now, via 15 percent All India Quota for SC Category, 440+ marks would be a safe score for getting admission in a government medical college. If you want admission in A.P. with the marks of 400 in neet 2020 then I suggest you to use college predictor tool of careers 360 fot NEET 2020 to predict best college on the basis of your marks here:

https://medicine.careers360.com/neet-college-predictor?icn=QnA&ici=qna_answer

Hope it will be helpful for you :)