I'm just about to finish an MBA and at 30, am around the average age in my class. There are quite a few classmates in their mid 30's so I don't see any problem with you finishing up at 36. This is the typical age profile in Europe, while in the US it tends to be quite a bit younger.
It's worth bearing in mind that some post-MBA opportunities may depend on age. If you haven't got into banking or consulting by now, it may be difficult to break into these through the traditional routes. Also, some of the industry rotational programs aimed at MBA graduates are looking for a youngish profile that they can mold into their corporations.
I guess it depends on what you are looking to use the MBA for. In particular, if you are looking to advance your current career or want to set up your own business, you will get a lot out of it. Best of luck!