Vertical Transfer Exam (DGS) and placement are made by ÖSYM.

You can apply for an adjustment for the courses you have taken and passed successfully in the associate degree program that allows you to enter ITU.

For detailed information about adjustment procedures

http://www.sis.itu.edu.tr/TR/mevzuat/muafiyet-intibak-yonerge.php 

Within the framework of the ITU Exemption and Adaptation Directive, which of your courses will be counted is decided by the exemption and adjustment commissions of the relevant Faculty.

Vertical transfer quotas are determined by Board of Higher Education (YÖK) every year and announced by ÖSYM.

Yes, in order to start undergraduate education at ITU, one of the language proficiency certificates determined by the ITU Senate must be submitted during registration or within 2 years after registration.

For the exams accepted by ITU and minimum scores;

http://www.sis.itu.edu.tr/EN/regulations/valid-english-tests-and-minimum-scores.php

During registration, the application process of the adjustment procedures is announced on the web page of the Registrar's Office. During this period, you must apply for an adjustment online, you cannot apply for an adjustment procedure other than the announced date.

No, you cannot.

You can transfer to Turkish programs of other universities with your Central Placement Score before you are dismissed from ITU due to failure in the preparatory class.

If you are dismissed due to failure in the English proficiency exam at the end of the second year of the preparatory class, if you wish, in accordance with Article 9 of the "Regulation on Foreign Language Education and Teaching in Foreign Language Education in Higher Education Institutions", you can apply for transfer to universities where English education is not compulsory. You can find information about the application process on the web page of ÖSYM.