After downloading to Lollipop 5.1.1 via wireless my phone keeps on booting, why won't it leave that screen?

[Said Sinare]

after downloading to lollipop 5.1.1 via wireless my phone keeps on booting it wont leave that screen

I undated my s6 to lolipop 5.1.1 after downloading it , it restarted and it wont leave the booting mode . It keeps on restarting. I need help restoring my phone