It's great that you have managed to rescue this budgie and are trying to reunite him/her with their family. Besides advertising online and if you haven't done so already, you can also post flyers near in the neighbouring area you found the budgie, nearby pet stores, vets, etc.
The information on this link may also be useful: https://talkbudgies.com/lost-found/35...questions.html
Best of luck with everything!
RIP sweet Tito (Summer 2008 - January 17th 2013).
You are missed and never will be forgotten.