Hello Zeenat,
The EWS quota is for economically weaker section students of general category. The students belonging EWS quota has 10% reservation in general category. From last years' trends it is noticed that student need low score for admission as compared to students from general or obc category.
With 420 marks you have chances of getting admission in Govt. Ayurvedic College, Nagpur.
As cutoff ranks varies every year, you may use below college predictor tool to check your chances in your dream College based on your rank :
https://medicine.careers360.com/neet-college-predictor?icn=QnA&ici=qna_answer

Hope it helps.