GRUB loader not shown - Dual boot Windows 10 and Kali linux 2016.2

[_defalt]

The grub should be installed in the EFI partition so you have to mount EFI partition too along with your root partition. Run these commands and see if it helps:

sudo mount /dev/sda5 /mnt
sudo mount --bind /dev /mnt/dev
sudo mount --bind /proc /mnt/proc
sudo mount --bind /sys /mnt/sys
sudo mount /dev/sda2 /mnt/boot/efi
sudo chroot /mnt
grub-install /dev/sda
update-grub
exit
sudo umount /mnt/dev
sudo umount /mnt/proc
sudo umount /mnt/sys
sudo umount /mnt