It can be an adjective:

gittiği şehir
the city that he went

yaptığı yemek
the meal that she cooked

I wrote past tense "went" but there is no time. It can be any time; "the city that he goes"; "the meal that she cooks" (or can be future too)

but if you want to say the time exacly for future, you should use future form:

gideceği şehir
the city that he will go

yapacağı yemek
the meal that she will cook

It can be a relative clause:

Ne yaptığını bilmiyorum
I don't know what you did

There is the same time situation. We can't sat that it is exactly past. It can be anytime: "I don't know what you are doing", "I don't know what you do", "I don't know what you'll do"

But if you want to say that the event is in future you may use its future form (like the previous one):

Ne yapacağını bilmiyorum
I don't know what you will do

Other examples;

Gittiklerini görmedim
I didn't see that they went

Ahmet'in kaybettiği para ne kadar?
How much is the money that Ahmet lost?

Sıkıldığını biliyorum
I know that you are bored (or you are getting bored)

Sana, sevdiğim bir şarkıyı dinleteyim
Let me show you (make you listen to) a song which I like

Another example from the song Severek Ayrılanlar by Ayna

[...]
Çok uzak bir şehirde beklendiğini bilerek
[...]

By knowing that s/he is waited in a far city

Song and the lyrics are here:
http://www.turkblog.info/ayna-severek-ayrilanlar