I want full documentation of civix tool for creating civicrm extension. I already saw a document on github. I need more information about civix.
The chapter on civix is at https://docs.civicrm.org/dev/en/latest/extensions/civix/
If you have specific questions after reading the documentation then ask here.
You might want to check if there is a CiviCRM partner/expert near you that would be willing to organise a developer training (or give you a private one). You will probably have to pay for it but it might save you quite some headaches trying to figure it out on your own.