You have the right idea! Not sure that ring will do it though. There are plenty of people out there doing the same thing only using different techniques.
Tile method. Drill a hole in a ceramic tile just big enough to run the roots through and repot tile and all.
Washer method. Same as above only using a large washer from your local hardware store.
CD method. What else are you going to do with that ABBA disc now that everything is digital?
Whatever you got method. The idea is the same. When the tree grows large enough whatever you have around the trunk will constrict the growth and force the tree to put out new roots.
The problem I see with your current attempt is that the wire may not be strong enough to restrict growth. Also, if a new nebari is your goal, why not get busy on that right away and crank that wire down? There is no need to put that off, other than you have your trunk training wire inside the ring , and that really should not be an issue. You can cut that wire when it has served its purpose or just let the tree grow around it.
Totally understand the no rush attitude. Patience is part of Bonsai after all. However, why wait to develop something later when we can work on it now? In 5 years do you want a nebari that had been in development for 5 years or 2 or 1 or none?
Hi @Amitdesai1978
I think your seedling will probably eat the bit of wire for breakfast without throwing a single root i.e. it will grow around it. @andy2sheds idea of a tile or washer will work much better, but no guarantees. I have tried to get pines to throw roots with girdle technique and grafting and had zero success, so all I can tell you is what dosen’t work.