My father is here in the US with a 10 year multiple tourist visa and we have this belief that he can only stay here for 6 months and will have to go back to country of origin in order to be able to return to US in the future. However, my brother who is in the military is going to petition our father for green card while he is here but father is in his 5th month now and we were wondering if there is a way to extend his stay here while going to wait for his approval. Do we still have to file for extension of his visa. If yes, what form will he fill out? Also, where do we mail or submit the application? I heard that it's different from regular application since military petition is a priority so we thought maybe they have a different address?