It's possible to restore data deleted one month ago?
If you've deleted the pictures within the last 30 days, they are still available in the "Deleted pictures" album/folder within the Photos app on your iPad. If the deletion occured more than 30 days, they are unfortunately gone.

While it might be possible to recover the data even after the 30 days, the sandboxed architecture of iOS, the hardware encryption used and the ongoing file system writes by other apps make this a rather theoretical approach.