hello i am using apple iphone 4s... but i cant use this option, i can not see the option "personal hotsopt"... please help me..

Does your cellular provider offer a tethering plan?

Have you subscribed to a tethering plan?

If you're on a carrier that supports tethering, and have the additional tethering feature on your cell phone plan, then Personal Hotspot can be found/used in Settings -> General -> Network. If you do not have the tethering feature, then you'll be prompted to add the call your carrier to set it up. Hope this helps.