My iPhone is not available for Hotspot?

Hotspot is not available unless your carrier supports it and it is part of your plan.

You are not addressing Apple here. This is a user to user support forum. If your carrier supports Personal Hotspot and your account is provisioned for Personal Hotspot, you should find the ability to turn it on in Settings. If you do have that and cannot get it to work, then see this support document for troubleshooting help. http://support.apple.com/kb/TS2756