hi, in recovery mode, if itunes is not opening automatically, what to do?

Not entirely sure what you mean, but if your computer's iTunes isn't opening when you connect the iPad to it then open iTunes yourself prior to connecting the iPad.

If you mean that your iPad isn't being recognised by your computer's iTunes :

PC : iPhone, iPad, or iPod not recognized in iTunes for Windows - Apple Support

Mac : If you don't see your connected device in iTunes for Mac - Apple Support