You cannot belong to 2 categories at the same time. EWS category is for those students who do not benefit from any reservations lile OBC, SC,ST. They are general category candidates whose annual income fromnall sources is less than 8 lakhs per annum. There is a subcategory in OBC which is non creamy layer. It is for those whose belong to OBC and their annual income is less than 6 lakhs per annum. So you cannot belong to OBC and EWS.  Based on data from 2018, 501 is a less score for both OBC and EWS categories for government medical colleges. You might get a seat in a private medical college.

Yes, since you are belonging to OBC and ews category,  you can be able to get a seat in government Medical College in Odisha .

According to last year's data analysis, there are chances that you may get a seat in Pandit Raghunath Murmu Medical College and Hospital, Baripada ; SLN Medical College and Hospital, Koraput ;Government Medical College and Hospital, Balangir or Government Medical College and Hospital, Balasore.

Hey!There
Seeing your score and previous year cuttoff of medical college,you seems not elligible for goverment Medical College.You need score 550+ for goverment Medical College.This year cuttoff will go high as paper was easy.
Visit below mention link to know previous year cuttoff of medical college of odisha:
https://www.google.com/url?sa=t&source=web&rct=j&url=https://medicine.careers360.com/articles/neet-cutoff-odisha/amp&ved=2ahUKEwiA8eyEvYfjAhVCXn0KHYoVDqcQFjACegQIARAB&usg=AOvVaw0g7ZIDQspylg92_gpUzqEn&ampcf=1.
GOOD LUCK!