I replied in another channel where this was cross posted. Basically I think the problem is that your father doesn't know whether he's going to be relocated somewhere else. That probably is not his decision. He's getting frustrated with the repeated questions because HE would like to know if he's going to move also, but he doesn't, so he can't answer your question either.

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I did a big write up in /r/expat on the cross post of this question about how to approach it, but basically the answer is probably:

1. He doesn't know the answer to your question
2. He may know who is making decisions that will affect your answer -- ask him about that, and what they'll base the decision on
3. He probably doesn't know when the decision will be made