For what I know, BluRay will connect only to HDCP-compliant sets, so no converter would do the job for an old TV.
Then - why cripple hi-def BluRay on old lo-def TV?
Finally - why connect that "Android box" to BluRay in the first place? May be you woudl be able to connect it directly to the TV (it depends what outputs this box has), or thru an adapter. Again - you will lose a lot of quality.