Shashank, the Community that you belong to in Telangana should also be listed in the Central OBC/SC/ST list and also should belong to the same Category that it belongs to in Telangana. For example, if you belong to OBC Category, the Community you belong to should be listed in Delhi OBC Category and also Central OBC list. Then you claim OBC benefits or else you will be considered under General Category. And regarding the Caste certificate, you have to apply for Haryana Caste certificate because that is where you hold the domicile from.