Question on contested adoptions

I had a couple questions on contested adoptions. When can a biological relative of the child step into the picture. Is this before TPR. I hear of so many cases of where an aunt or distant relative comes into the picture. Does it matter if the adoption is not finialized or are all rights lost at the TPR? Also how long is the appeal process after the TPR, I know it varies by state, but I can't seem to find it anywhere on my state pages. Thank you for the information