Processing Time for Status Change from B1 to F2 or for B1 Extension

[JimmyVzla]

I am under B1 accompanying my wife F1 she needs to study 6 more months until March 31st, about 7 months from now. I want to change my status but I need to be certain that I will get the status change before March 2017. Perhaps is it faster to extend my B1 to 6 more months? I have been here since March this year and should leave by September 20th. if the timing is not on my favor I would have to go back to my country and apply for visa F2 from there but that is the last option sinceI I would have to leave my family alone. Thanks for your help