Various Options are Available for you

The first step is to diagnose the problem. Was the data lost by accidental deletion, is the file system corrupted, or is there a problem with the disk or other hardware? If the problem is with the hardware, the disk may have to be taken into a clean room. The clean room is a room where the microscopic dirt and dust is kept down to a point where it cannot damage the microscopic electronics and components of computer hardware. A hardware engineer will work on the disk and get it operational without affecting what’s actually stored on the disk.
Once the disk is operational, the data recovery engineers will make a copy of the entire disk. Then they can start restoring the file structure and make a list of all the directories and files on the disk. They will also test each file for damage and make repairs if possible. Finally, they can put the restored file system and repaired files on a new drive for the customer.