hangi bölüm dicem de ne bekliyor acaba ?

 I wonder what he /she is expecting and I will say which section/part

my try

"de" functions as "but" here.

Again, without the context I will guess;

"I am gonna say [ask] [if] which department [part,section] is she[he].[studying at]....but I wonder what is she[he] expecting [me to say [ask]]  ?

Or ;

" I will tell him[her] which department [subject] I am studying [at the uni] but I wonder what is he [she] expecting me to say ?