Thank you for your question. 

All india quota seats were between 546 to 600 marks(government ones)

State quota seats between 470 and 500 and above.

Now, the private institutions have a low cutoff score, that is true.

You will get a seat if you have scored above 400 and 450.

Donation is illegal. The college can only charge tution fees and hostel and mess charges.

Good luck