how can I enable IOS6 tethering without jailbreaking my Sprint iphone 4s phone?
You need to have the "Mobile Share Plan" enabled first from your phone service provider. To see if you have it, find Personal Hotspot. It should be in Settings -&gt; General -&gt; Network -&gt; Cellular Data Network. Please see this article for more information. 

Like I said, if you do not see the option for Personal Hotspot, confirm with your carrier that this feature is supported and your wireless plan is configured for Personal Hotspot.