Which Flash should I purchase for my Nikon D3200?

I've shortlisted 2 Flashes for the use:
Metz Mecablitz 24 AF-1 Digital (for Nikon) Flash

OR

Nikon Speedlight SB-400 Flash

Let me know which one should I purchase from the above. If there are other options you wish to give me for purchasing the Flash for Nikon D3200, then do let me know.

Thanks in advance!

Added (1). The budget is till 7K INR

While the Metz is slightly more powerful than the SB400, neither of these two flash units are very powerful.

Not a lot more powerful than what you already have on your camera's internal flash unit, so you are not really gaining a whole lot.

They are lower power than a SB-700, which I would consider minimum for an external flash unit.

Go for something appreciably more powerful than your built-in unit, and buy the most powerful, compatible flashgun you can afford.

There are many ways to reduce the output of a big gun, there are none to increase the output of a small one.

Both of your flash choices are a waste of time and money.

You don't mention a budget, which makes a lot of difference.

Metz has another flash at the low-cost end, the 36, that would be a better choice than either or yours. It's only slightly more expensive than the 24.

The least expensive flash on the market with enough power to make it worth the effort is the Sigma 610 DG ST, at about $150. They do make one that is fully compatible with your Nikon. This has the power of the SB-900 at 1/3 the cost, but it does not have all the bells and whistles of the Nikon unit either. It would seem that you are new to flash units, so you won't even realize those features are missing.

As stated above… When it comes to flash gear, get all the power you can. You can't have too much, but it is easy to not have enough.