Well regarding 2k OBC rank it is equaivalent of around 11k CRL rank.

So to achieve 11k CRL, you need to having around 140 marks in JEE advanced looking at the difficulty level and the previous year analysis.

But my personal suggestion would be that you cannot expect much from 2k OBC rank, so I would recommend you to al=tleast aim for 1.5K rank so that you can expect a decent seat at decent IIT.

Thank You