As of January 1, 2017, all phones in India -- including iPhones -- will have to have some form of panic button to improve the security of women in the country, according to a new government order.
By January 2018, all phones will also have to have built-in GPS, said the Indian Express. That should allow a phone's location to be shared when the panic button is hit. iPhones have had GPS since the iPhone 3G.
In the case of "feature" phones, people must be able to trigger the panic function by hitting the 5 or 9 keys. The situation becomes more complex with smartphones however, most of which don't have a numeric keypad.
Instead, those devices will either have to add a dedicated button, or tie the option to an existing power button. The latter is more likely in the case of iPhones, as Apple normally avoids making region-specific hardware changes unless it involves supporting local wireless networks.
The Indian government is suggesting that companies going that route use a triple-click command, which would be relatively easy to implement in a future version of iOS as a region-specific setting.
iOS already has a pair of emergency functions, including Medical ID and the ability to dial emergency numbers without unlocking a device. India's panic button is meant for cases where an incident like rape or assault is imminent, however, and there might not be time or opportunity to dial as usual.