You can recursively flatten the data like this
>>> def rec(current_item):
... if type(current_item) == list:
... for items in current_item:
... for item in rec(items):
... yield item
... elif type(current_item) == int:
... yield current_item
and then sort it like this
>>> sorted(rec([1, [3, 6], 9, [2, [1, 3]], [4, [1], 5], [6], 1, [[2]]]))
[1, 1, 1, 1, 2, 2, 3, 3, 4, 5, 6, 6, 9]