Hi,
I formatted an external hard drive with a lot of files, and after recovering most of them with Recuva, I was stuck with a couple corrupted braw files.
After many many tries and different softwares, what worked for me was Wondershare Repairit. But to get the file ok I had to provide a sample file recorded with the exact same braw settings (frame size and same time of recording, or a little more). So I had to record that sample file to use it with the program.
Careful! Recoverit has a monthly payment, so remember to cancel your suscription before they charge you again!

(not afiliated with them in any way, just telling you what worked for me)