Win 10 RHEL 6.7 dual boot issues


I have had a hunt around the forum to find an answer to this but I have been unable to locate anything and was hoping someone could assist me.

I have the following OS setup on a laptop, and I am unable to boot into redhat, but I still have full access to Win 10. There are no reported errors on the drive.
BIOS Legacy
OS 1 Win 10
OS 2 RHEL 6.7 - grub in RHEL partition

I have tried the following
Grub Legacy - comes up as hard drive error
Grub 2 picking the drive - boots into Grub4DOS
Grub 2 auto locate - boots into Grub4DOS

I have tried with and without the Metro boot loader (not sure what this actually does) and on 2 different systems with the same outcome.

Any assistance would be greatly appreciated.

Lee G