Your grub is borked you need to reinstall the grub
To fix GRUB 2, you need an Kali Live USB from which you need to boot. Once you boot to the LIVE CD, open a terminal an and type these commands:
Firstly, you need to find out on which partition your Linux system is installed:
sudo fdisk -l
most of the time it is "sda1"
Now, we must mount that partition
sudo mount /dev/sda1 /mnt
Where "sda1" is the partition where you installed Kali (or any other Linux distro). It could be "sda5", "sda6", or whatever.
Install grub to the partition you've mounted:
sudo grub-install --root-directory=/mnt/ /dev/sda
Important: Please notice that it's "/dev/sda", not "/dev/sda1". "sda" is the hard disk on which your Linux distribution is installed!
Restart your computer. As previous Grub 2 entries are removed, run the following command to restore them: