How to find the manufacturer of iPhone?

Since Apple is the only manufacturer of phones, I assume you mean you want to find out what carrier it's locked to...

All iPhone's are manufactured by Apple.

I am wondering if the OP is wanting to know what is the company that Manufatures the iPhone?

Ah, you mean what country the phone was manufactured for.

LL = USA - AT&T

If you want.

iOS 6 Beta is only available legitimately to registered iOS developers who have paid to join the Developer Program and get early access.

It is not available publicly unless you have downloaded it illegally.

iOS 6 beta is not to be discussed outside of Apple's Private Developer Forums. If you are are Developer, go to http://devforums.apple.com/

If you are not a developer, and have download iOS 6 beta illegally, we cannot help you.

"How to find the manufacturer of iPhone?"

If you're in a taxi, or on the road, drive north of Shenzhen, China. Oh, do you mean "which company manufactures the iPhones for Apple?" The answer is "Foxconn".