is there any atheist community in Turkey?

[Permafrost]

Given the overwhelming influence of Islam it looks like you're studying at one of those crappy so-called universities. When I was studying in Istanbul (ITU) almost all students were either atheists or theists.

As CMV noted, most Turks will keep their non-belief to themselves because Muslims hate to be told "there is no Allah" and even get aggressive to the extent of physical attack. Though some people are openly atheists and may legally state whatever they want so the situation overall is relatively better than of other Muslim-dominated countries.

If your intention is to meet modern people yours then you can try certain places online, including Twitter or ekÅŸi sozluk. Most atheists can speak English.

And there is a newly founded Atheism Society. https://www.facebook.com/ateizmdernegi
These folks are pretty open-minded and so feel free to contact them. Good luck!