Since the 1.2 update there's no longer the option of rendering more than 6 chunks. Before it was 16 chunks I believe.

There used to be an option of rendering a lot more chunks than 6 in Minecraft Pocket Edition. Now I can barely see anything in my world unfortunately. The max number of chunks I can slide the option to on settings is 6. On my friend's iPhone 7 plus running iOS 10 or later he can still render 14 or 16 chunks like it was before.