Hi
 It's  difficult to make prediction  but when we go through previous year trends then
 In neet 2019 ,  518 marks for obc category was the cut off marks/ lowest marks  that got an mbbs seat in Government Medical College, Omandurar Estate, Chennai under Tamilnadu state quota
 You can check the same at
 
  https://medicine.careers360.com/articles/neet-cutoff-tamil-nadu
 
 
 But yes,
 cut  off   marks / rank   for medical colleges keeps changing every year  depending upon various factors like
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   number of students that appeared in the neet examination,
   
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   kind of marks obtained by students  in neet ,
   
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   toughness level of the neet examination,
   
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   number of seats available etc.
   
 
 So ,  in your Neet 2021 Examination to be on the safer side, so you should target at least 30- 50 marks more in comparison of neet 2019 i. e , you should target at least around 550 marks .
 Now that,
 limited time is left for neet 2021 , so you should be focusing on your preparation,
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   practising chapterwise questions
   
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   then revising the chapters,
   
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   solve at least previous 10 year neet question papers as concept behind the question often gets repeated in the examination so it will be of great help in your preparation  ,
   
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   go through neet mock test papers as it will let you know your preparation level and and weak areas so that you can work on them and perform well in your examination.
   
 To help you in your preparation we have neet knockout, the link for the same is provided below :-
 
  https://learn.careers360.com/knockout-neet
 
 
 Thank you