Hello, Kritika 

Congratulations you have secured a good score but it will be difficult to say you will definitely get a government college because cut off is different every year depending on Category, Home state quota difficulty level 

However, 550+ is a good score to get a government college and you have 581. You have a great chance of getting a good government college

I'm providing you a link which will be useful

https://medicine.careers360.com/neet-college-predictor

Hope this helps you if you have any queries you can add in comment section

Thank you