Ofcourse you can apply under the category of obc category As per the Ministry of Social Justice & Empowerment (government. Of India),  RBA full form is residents of the backward areas of the society which comes under OBC category but some university or entrance exam dont consider it as obv category for confirmation you need to check proper notification of exam. OBC is other backward classes which has 27 percent reservation in government organisations you can avail benefits of the same depends on the organisation or institute you want.