´It was narrated from 'Abdullah bin Ja'far that:` The Prophet [SAW] used to wear his ring on his right hand.
Related hadith on this topic
Explanation & Benefits
Shaykh Umar Farooq Saeedi
Benefits and Issues:
The Sunnah and recommended (mustahabb) practice is to wear the ring on the right hand and to wear it on the little finger or the finger next to it.
Source: Sunan Abu Dawood – Commentary by Shaykh Umar Farooq Saeedi, Page: 4226