I have got 28 marks and an OBC rank of 193679, which college should I take admission in?

You can get colleges of your state May be government colleges. Try JEE college predictor to get more information and insight about college which you can get on the basis of your rank- https://www.shiksha.com/b-tech/resources/jee-mains-college-predictor?utm_source=connect&utm_medium=CR_JEECP&utm_camp