The new software allows 36 iPhone carriers and 23 iPad carriers around the world to provide access to the faster LTE networks offered in many locations.
Apple's marketing chief Philip Schiller said iOS 6 "is the world's most advanced mobile operating system, and with nearly 300 million iPhone, iPad and iPod touch devices on iOS 6 in just five months, it may be the most popular new version of an OS in history."
The update includes support for Apple's voice assistant Siri in more languages, an Apple statement said.
The statement noted that it will include maps "with Apple-designed cartography, turn-by-turn navigation and Flyover view." Other features including Facebook and Passbook, Apple's system for storing tickets, coupons and other financial data.
The new iOS 6.1 is available as a free software update.
Apple shares rose 2.2 percent Monday to $449.55, but remain down some 35 percent from last year's record highs amid concerns about slowing growth for the US tech giant.