There are 3 methods you can try to bypass 3 Mobile’s internet tethering USB or Hotspot block.
1. User Agent switching
Mobile carriers usually know when a person is tethering by detecting the browser type they are browsing for. PC and Mobile browsers have different user agent names and this is how they find out. You can go to Chrome store or Firefox add-ons and install User-Agent switching extensions. I usually choose the Google bot user-agent from options the User-Agent extension gives me as that has worked for me in the past on GoSmart mobile.
Tor has ability to bypass more than just tethering blocks. It is also used to bypass website blocks, public Wifi captive portal blocks and more. It wasn’t designed for bypassing stuff but designed to keep people anonymous.
Another method you can try that doesn’t require installing anything is just to type HTTPS:// before the domain name you are visiting. Most sites support SSL these days, and so by visiting the SSL version of the site you can actually fool the hotspot blocker causing it not to know know what website you are trying to visit or what your user-agent is. The https:// has even worked on web filters that were installed at a Hotel which allowed me to access a Reddit subreddit that isn’t normally accessible without the https:// This https:// has also worked on GoSmart Mobile tethering block. Good luck and happy surfing :)