Please help, my windows phone unable to start Cortana
Cortana is may not be available with the language you selected. To make cortana work in India, activate Cortana Alpha Version.
Steps to activate Cortana alpha version:
If you've changed region or language settings previously to try out Cortana when it released for the US, revert to the original settings for your country. A restart maybe required if you change these settings.
If you haven't, confirm that the settings are in order.
Language: English (India)
If you've not made any changes before, you'd need to start here and just change your speech settings.
Speech: English (United Kingdom)/English (United States)
This will ask you to install an Update for other language support. Do it.
Now, tap the search button, and you'll have Cortana greeting you rather than the vanilla Bing screen. It's an alpha version, so things might be awry or some features may not be available.