How to start appium server programmatically for v 1.6.3

HI,
Am trying to test on 2 iOS devices simultaneously as we have requirement to do operation on one phone and verify on the other. so trying to launch appium server and create 2 iosDrivers. please help.

Env:
iPhone 5c and iPhone 6

iOS 10.1.1
iOS 9.3.4 or 8.2