Does a child have inheritance claim against a natural parent whose parental rights were terminated? Child has been subsequently adopted by others.

Short version -- almost certainly not.  A termination of parental rights (in Nevada, at least) is a complete dissolution of legal ties -- rights and obligations -- in both directions.  Other states may have different laws, so the place of the order might be relevant.  Of course, any person can choose to make a beneficiary designation to someone else, so if the terminated parent chose to make a bequest to the child adopted by others, he or she could do so.