Well regarding this 2019 JEE advanced paper, after the experts of varied coaching institutes, analyzing the difficulty level and previous year's cut-off, it is expected that cut-off for OBC-NCL would be around 90-94 marks. 

Since for getting a least rank for an IIT in OBC, you need to have around 115 marks and since now you being a girl which is another added advantage, so you can expect a seat at 110 safely.

Though the above is a calculated estimation from the ebst of my knowledge so I would recommend you to wait for the official answer key to release.