The New York City Council enacted one of the nation's toughest anti-smoking measures, banning smoking in many stores and other public places and restricting it in offices and restaurants. The bill, which Mayor Edward I. Koch is expected to sign, forbids smoking in theaters, sports arenas, public restrooms, taxicabs, concert halls, banks, museums and hospitals, as well as larger retail stores. It requires nonsmoking areas in other public places, such as offices, public transit waiting rooms, hotel lobbies and larger restaurants. The measure, which was passed on a 30-1 vote, carries a $50 fine for individuals who smoke where it is banned. Business establishments would be subject to $100 fines for failing to adhere to the law, increasing to $200 and then $500 for repeat offenses. The new ordinance is scheduled to take effect this spring after public hearings.