I would like to ask, what are the Turkish restrictions on clothes from China, and are they cleared at Istanbul Port?

I don't advise you to do this. It's too difficult. . . .

Turkey itself is a textile power. Textile I is cheap, and the barriers of textiles and sweaters imported from China are unusual. To clear customs in Istanbul, first of all, you need a quota, second, the tariff is too high, and other documents are second. All these are ok, but you can guarantee that if you add various fees to customs clearance, your clothes will definitely be unprofitable or rare in Turkey. Moreover, the customs clearance in Istanbul is extremely harsh, and it will cause a lot of losses if you are not careful.