Unmet dependencies while installing Git on Debian

You should edit your sources.list , by adding the following line:

deb http://ftp.ca.debian.org/debian/ jessie main contrib

Then upgrade your package and install git:

apt-get update && apt-get upgrade && apt-get dist-upgrade
apt-get -f install
apt-get install git

Edit

the following package git , liberror-perl and [rsync]3 can be downloaded from the main repo , because you don't have the main repo on your sources.list you cannot install git and its dependencies .

Your sources.list should be (with non-free packages):

deb http://ftp.ca.debian.org/debian/ jessie main contrib non-free
deb-src http://ftp.ca.debian.org/debian/ jessie main contrib non-free

deb http://security.debian.org/ jessie/updates main contrib non-free
deb-src http://security.debian.org/ jessie/updates main contrib non-free

deb http://ftp.ca.debian.org/debian/ jessie-updates main contrib non-free
deb-src http://ftp.ca.debian.org/debian/ jessie-updates main contrib non-free

deb http://ftp.ca.debian.org/debian/ jessie-backports main contrib non-free

On debian Stretch your /etc/apt/sources.list should be (at least):

deb http://deb.debian.org/debian stretch main
deb http://security.debian.org/ stretch/updates main 
deb http://deb.debian.org/debian/ stretch-updates main

Try apt-get update && apt-get install git-core.

I found it in here.