correct sentence: Bilakah kita dapat berjumpa lagi? apabila is suitable use in middle of sentence .. Bila or bilakah for a begining sentence of asking .. but still apabila, bila and bilakah are the same meaning of when. it just correct place to put in the beginning or in the middle. :)

It depends on the sentence, but if you want to say:- Bila kita akan berjumpa lagi? ->When we gonna meet again?