I have a broken finger which was broken at the joint on my ring finger i am now in therapy is there a possibility my finger won't work the same again?

Should be normal: Most broken bones heal well and with diligent occupational therapy you should recover full function. When a break goes into a joint, there is always a concern of stiffness or developing arthritis long term. Stiffness can be limited with therapy. As long as the break is isn't very complex and it heals well, long term arthritis isn't very likely.

There is a: possibility….a doctor who sees your X-ray would have a better idea..

Not just bone...: The fractured bones are one thing. The potential soft tissue damage incurred at the time of the fracture, are something else. Whether or not full function is restored is a combination of how these two types of tissue can recover from the trauma. This is where the sciences of both physiotherapy and rehab come into play.