Free Economic Zone for İT companies in Istanbul

İSBİ İstanbul İhtisas serbest bölgesi is a free economic zone established specifically for the operation of companies whose field of activity is high technology. 
Companies registered in İSBİ are provided with a number of benefits such as exemption from VAT and stamp duty, staff income tax and customs duties, corporate tax, etc. Entrepreneurs can register either a brand new company or a branch of a local or foreign company with İSBİ. For more information, please visit https://www.isbi.com.tr/Default.aspx in Turkish and English.

To register in the free economic zone, you need to:

make a one-time payment of $5,000 to the Central Bank of Turkey
fill in the application form to the İSBİ General Directorate
Receive the result of the application (if the license is denied, the payment of $5,000 will be returned)
Go through the procedure of obtaining a license

You can see the steps and application form here: https://www.isbi.com.tr/Yatirim.aspx?SayfaID=3.