How to restore grub2 menu after installation of Windows 10

Hi I have installed Windows 10 and so in order to restore grub I have booted into rescue mode using opensuse 13.2 disk and followed the procedure provided in the following link

At present when I am in rescue mode and after issuing the command grub2-install /dev/sda I am getting message as installing i386 grub and finally after rebooting I am getting a blank screen with no entry for Opensuse 13.2.

Help me to restore the grub menu.

Do your openSUSE and Windows use legacy BIOS or EFI installation types?

If you mix modes it won’t work right.

As I am new to EFI can you please explain about these and how to find whether my operating systems are using legacy bios or EFI.