I wanted to know the advantage and disadvantage of building titanium from source?
Which will be better in terms of pricing licensing - Titanium from App explorer or titanium from github?
What I can leverage if I go with the Github?
As I am confused that if I build any commercial application or an application that generates revenue, so do I have to pay royalty to Appcelerator.
You do not have to pay any royalties to use Titanium SDK, or distribute Titanium apps on the app store, there is no reason at all to compile it from source. You only pay if you want to purchase specific modules from the marketplace, or want dedicated support from Appcelerator itself, or want to use a large volume of ACS.
You do not gain anything (if your just getting started with Titanium that is) by compiling from github except pain, suffering, and compile fails.