Hi Mayank

sudo git clone
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git
Initialized empty Git repository in
/home/mayank/linuxkernel/linux-stable/.git/
^[[Agit.kernel.org[0: 149.20.4.72]: errno=Connection timed out
fatal: unable to connect a socket (Connection timed out)

I tried disabling firewall also but that is also of not help.

Any reasons why this error is happening and how can i get over this.

Most probably your company's firewall is blocking the git protocol.
You can try to clone using http or https url instead of git url.

-- 
Manavendra Nath Manav