ios 9.0.2

Hi inderjitsinghfromnull,

I have two articles for you that will help you address this issue with your inability to install the iOS update. See the following article if you are trying to install this update from an over-the-air iOS update:

Resolve issues with an over-the-air iOS update - Apple Support

https://support.apple.com/en-us/HT201435

And use this article if you are receiving an error when attempting to update from iTunes on your computer:

Resolve iOS update and restore errors in iTunes - Apple Support

https://support.apple.com/en-us/HT201210

Thanks for using the Apple Support Communities. Have a good one!