Changin Turkish Lira in Romania, Serbia, poland, Germany

In Warsaw there are quite few exchange offices that would take your Turkish Lira. Here's a list of those that have non-rip-off rates:
- at 'Joder' (address: Puławska 49) you'd get 1.7 PLN for 1 TRY [http://joder.kantory.pl/kursy-walut.html]
- at 'Apollo' [http://www.kantor.waw.pl/] in Galeria Mokotów and BlueCity shoping malls and 'Wiek' in Arkadia [http://www.kantor-wiek.pl/arkadia.php] you'd get a bit better rate if you exchange more than the equivalent of 5000/3000 PLN respectively.

Currency from funny countries - including many Balkan countries - should be spent locally, as changing abroad is often difficult, expensive or impossible. Your best bet in Bucharest may be to try guests at the hostels, or hang around the train to Istanbul before it departs...

You can exchange Turkish Lira in Serbia only in theory. Almost all exchange offices won't bother with that.

in Romania you can change Turkish lira in Bucharest, at Dristor Exchange which has 2 locations in Central bucharest.
One is at Marasesti 42. And the rates are good.