Microsoft's Cortana person assistant software made its debut with Windows Phone before finding its way to Windows 10. As it stands, Cortana is available on Android as a beta and if you're wondering how useful it is, you might be interested to learn that, in the latest beta, Microsoft has activated the "Hey Cortana" feature. Microsoft has yet to announce an official non-beta release date.
According to Android Central, as of version 184.108.40.2069, you can get Cortana to listen for spoken commands simply by saying, "Hey Cortana"-a little like Google Now's "OK Google" and Siri's "Hey Siri" hands-free modes". It may be a while before businesses have all been mapped out for Cortana, allowing people to find their nearest rest stops, restaurants, etc. Regardless, it's great that people in India are able to make use of Cortana without needing to fiddle with the settings of their device.
In order to access the feature, Android users must update the beta app and simply enable the option "Hey Cortana" option.
Cortana is still a fledgling assistant and even more so on Android. However, there is a small limitation and that is your phone's display needs to be on for it to work.
The problem is not unique to Cortana. There also aren't very many phones that have support for Google's "OK Google" hotword because it requires device-specific drivers, which means many Android users on Google Now still have to unlock their phone screens to activate Google Now via voice.