Unless your company is one of the few exempted by the law, (not given the option) then you've been lied to. There are very few exemptions and they're spelled out relatively clearly.There are also exemptions for certain types of businesses within the law, my workplace was given the option to make their own rules and the director of security decided no weapons on the property. He's within the law. Nothing we can do about it.
Exempts possession of a firearm or ammunition: (1) on school property, on property used by a school for a school function, or on a school bus; (2) on certain child care and shelter facility property; (3) on penal facility property; (4) in violation of federal law; (5) on property belonging to an approved postsecondary educational institution; (6) on the property of a domestic violence shelter; (7) at a person's residence; (8) on the property of a person that is subject to the United States Department of Homeland Security's Chemical Facility Anti-Terrorism Standards and licensed by the United States Nuclear Regulatory Commission; (9) on property owned by a public utility that generates and transmits electric power or a department of public utilities; and (10) in an employee's personal vehicle if the employee is a direct support professional who uses the employee's personal vehicle while transporting an individual with developmental disabilities
http://www.in.gov//apps/lsa/session/billwatch/billinfo?year=2010&request=getBill&docno=1065