Unless Turkish is your native language, you can take Uluslararasi Türkçe Testi, abbreviated to UTT. Jointly provided by the Fatih University Tomer (Fatih Üniversitesi TÖMER) and the International Association for Turkish Language (Uluslararası Türkçe Derneği), it is organized depending on the number of candidates who have applied.
This exam is unusual in many ways. It is taken online, and, although it is recognized by many institutions at the highest level, there is a chance that some universities may not recognize it, and may require you to take additional tests if you wish to study with them.
Furthermore, the levels of proficiency are divided here into five levels, A1 through C1, leaving out the highest level, C2. You will also need to know the following about this test:
Once the test starts, you cannot take any breaks.
There is a fee for taking the test.
In order to pass, you need to achieve a minimum of 55%.
Remember to set your keyboard to Turkish before you start.
You should also bear in mind that passing a language exam is only one in a series of steps prior to a foreign student being able to enroll at a Turkish university. Almost every university will also require you to take the so-called YÖS, which usually comprises an IQ test, accompanied by a general knowledge or specialist knowledge test.