The person concerned can perform a preliminary search on Patent Office website in the Indian patent data base of granted patent or Patent Office journal published every week or by making search in the documents kept in the Patent Office Search and Reference Room, which contains Indian patents arranged according to international patent classification system as well in serial number. It is open to the general public from Monday to Friday, except Gazetted holidays. The public can also conduct search free of charge on the website of Patent Office. The person concerned can also make a request for such information under section 153 of the Act.