Hello Aspirant,

First of all let me make you clear that in IITs there is no reservation for Home state quota instead there is only All India quota and admission will be done only on the basis of your category or CRL rank.

As we go through the latest cut-off of 2020 then it shows that the closing rank for OBC category was 1108 for CSE branch in IIT Patna. See it is quite difficult to tell you about exact marks to score because for JEE-Advance no maximum marks are fixed but yes with regards to JEE-Advance 2021 if you secure your AIR in JEE-Advance under top 1100 in OBC category then there are good chances for you to get CSE branch in IIT Patna.

You can check out the latest cut-offs from the link given below :-

https://josaa.nic.in/Result/Result/currentorcr.aspx

Note that the above prediction is made on the basis of latest cut-offs available on official website of JOSAA and the cut-offs are bound to change every year depending upon various factors such as the number of candidates appearing in an examination, the number of candidates qualifying an examination, difficulty level of the paper, and so on.

To have a list of all those colleges which you can get based upon your JEE-Main score, category, and state you can use JEE-Main College Predictor :-

https://engineering.careers360.com/jee-main-college-predictor?icn=QnA&ici=qna_answer

As you are preparing for JEE-Main or JEE-Advance 2021 the I would recommend you to check the resources made by our experts to help aspirants like you in the best and smart preparation of JEE-Main or JEE-Advance 2021 :-

https://learn.careers360.com/jee-main-coaching/?utm_source=%20QnA

I hope this information helps you.

Good Luck!!