Yes, no sharing the cage! Plus, you don't know if the new bird has anything or not so it must be quarentiend away from your grey for about a month.
If you post a photo I could tell you what kind it is. There are many types of Ringnecks...Indian, African, Alexandrine, and some that are closly related like the Plum-Headed Parakeet and the Mustache Parakeet.