Since 1950, India has been implementing the most comprehensive affirmative action program in the world. Vertical reservations are provided to members of historically discriminated Scheduled Castes (SC), Scheduled Tribes (ST), and Other Backward Classes (OBC). Horizontal reservations are provided for other disadvantaged groups, such as women and disabled people, within each vertical category. There is no well-defined procedure to implement horizontal reservations jointly with vertical reservation and OBC de-reservations. Sequential processes currently in use for OBC de-reservations and meritorious reserve candidates lead to severe shortcomings. Most importantly, indirect mechanisms currently used in practice do not allow reserve category applicants to fully express their preferences. To overcome these and other related issues, we design several different choice rules for institutions that take meritocracy, vertical and horizontal reservations, and OBC de-reservations into account. We propose a centralized mechanism to satisfactorily clear matching markets in India.