Raid rebuild.

I have a client with a 5 year old Dell Power Edge 2600. This server has a Prec 4/Di raid controller with a raid 5. No one has kept this server up to date regarding firmware etc. One of the disks in the raid 5 broken so they shut down the server and replaced the drive. The raid controller never started to rebuild the new drive. I have been in to the menus of the raid controller and it has the option of rebuild or reconstruct the drive. Not sure which of the to use. I don’t want to delete the data, but get the raid fault tolerant again.

Thanks