yada and veya means or and both of them are the same yoksa means if not or otherwise " I haven't seen it used as or " . when turkish people wants to say "or " they use yada veya " if it's in a sentence" if it's a question they repeat the question mark " mi" . for example : - iyi mi kötü mü ?! ( is it good or bad ) - ne alacaksın ? uçak mı gemi mi ?! (what are you going to take ? plane or ship ?! ) for example : sport yapmam lazım, yoksa şişman olacağım . ( I have to do sports , otherwise\ if not I'll become fat ) I hope you understand it !! good luck

You can use, "ya da" and "veya" :)