Your query is a standard one many freshers get while passing out from college. To answer your query about the present, one needs to go back in time. Like Nathrao asked, what is your MBA's core specialty and, more importantly, why did you choose this over any other(s)? Is it that you went along with your friends, or did you have any specific reasons?
Coming to Your Primary Query
"Now In HR Field Which Department Is Going On Peak."
Please note that as long as you hitch your career to whatever field is in demand today, there is no guarantee and will never be any guarantee that this is the right choice for you. Choose whatever field where you are happy internally. If you focus excessively on money, position, or any external factors, there are bound to be situations when they will take a hit, and that's when you begin to feel, "Did I make a mistake?"
A quote by Zig Ziglar sums up what you can do: "Attitude and aptitude determine altitude." So, irrespective of whether the field is in demand or not, as long as you have the aptitude (meaning deep interest) and attitude (meaning willingness to go to whatever extent needed to make your mark), you can succeed in any field. And when you don't have any of these two attributes, it doesn't matter even if you are in a field that's the most in-demand field, you are bound to repent at some point in time.
Like Ashutosh Thakre mentioned, "choose a career for your satisfaction." And mistakes in such matters can be minimized when one goes into the field that he/she enjoys doing, else that would be just another job you do for a living and invariably has the potential to create unhappiness later on.
When you are unable to decide what's your mental nature or outlook (which is quite possible even for experienced persons), I suggest Google and find the many psychometric tests that are available for free. Take a couple of them to get some insights into your own nature—which points to the real you and not what one exhibits/projects/manifests outside—they can help you to decide which career line is most apt for you.
There's nothing "right/wrong" or "good/bad" in such decisions, only the most apt (or otherwise) for that individual.
All the best.
Regards,
TS