Hi, I am not an expert about Turkish grammer. I think Neden Niye, Nicin are the same however 'maybe there will be sligth diffirances between ' Neden" and the others. Because Neden strongly demands a reason from subject and subject is supposed give more detail I hope it is clear and make sense for you

The meaning of those words is exactly the same. There are some differences about translations. Niçin is the reduction of “ne için”. Translaton of it is “what for”. Neden/niye = why