The Samsung Galaxy Ring is an Android phone.
► Virgin Mobile answered your question in the Assurance Wireless FAQs:
Can I use an Android™ phone with an Assurance Wireless account?
No, an Android™-powered phone cannot be used with an Assurance Wireless account
► The Assurance Wireless plans will appear when setting up any payLo phone.
You can see the current line of payLo phones at: http://www.virginmobileusa.com/cell-phone-plans/paylo-plans/overview/#overview
You can find other answers on the Assurance Wireless website which can be found on this FAQ: http://virginmobileusa.custhelp.com/app/answers/detail/a_id/3340. Then click on the FAQ tab on their website.
Note, if you use Internet Explorer or Firefox you can search these ASK & ANSWERS by using the Search box above these questions.