Minimum marks required for an SC girl candidate for 85%quota and for Delhi medical govt.college too..

You need to have a percentile of at least 40% which means that your rank needs to be in top 60% of total candidates.
Remember! This is qualifying cutoff. This doesn't guarantee you a seat.

Cut-off scores for seat matrix are decided after the declaration of results.
However going by the previous year trends. A score around 475 would be good.
Personally I advise you to aim for at least 500.
All the best.