what will be my rank if i get 510marks

It seems you are asking about Neet. 510 out of 720 in Neet 2020 is a good score when you apply through state quota. Based on our Neet Rank Predictor Tool, you can expect a rank around 45500 to 55700 and respective expected percentile in the range of 96.54 to 97.04. Check out this link http://medicine.careers360.com/articles/neet-result
You have fair chances of getting a good government medical college.

To get the list of all possible colleges based on your rank and score, you can use our Neet College Predictor tool. http://medicine.careers360.com/neet-college-predictor?icn=QnA&ici=qna_answer This tool gives you a personalized report of the colleges you can get based on your score in the exam.