How to take a picture like this with nikon d5100?

What will be the iso, shutter speed and aperture setting? Do i need a tripod for this shot?

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A fast shutter speed. You need to be able to capture the splash. Here's a good link explaining that.
http://www.photographymad.com/pages/view/photographing-water-drops:)

Sure you could. I have a D5100 and I've taken water drop pictures with a much cheaper camera. I would start with lots of light and a low ISO, 100 or 200. A wide aperature, between 3 and 6. You can see that there's not much depth of field in this picture. And finally a really fast shutter speed. Something like 1/2000 to freeze the action. Timing the shot is where I see the biggest difficulty. Oh and yes a tripod and cable release.

Very fast shutter speed and a tremendous amount of luck. Yes, even with continuous shutter mode, luck is still needed.

No mechanical shutter is fast enough to get shots like this, the trick is to use the super fast short flash duration of a flashgun (strobe).

Camera on tripod, set up the scene, focus the camera onto your subject, shutter on B setting, totally dark room.

Open the shutter, which records nothing as the room is totally dark, drop whatever into the coffee and fire the flash, close the shutter.

Timing is the key, you can trigger the flash with several methods as shown here

http://www.hiviz.com/tools/tools.htm

Sound (the sound of the 'plop'), the object passing through a beam can all be used to fire the flash. Or you can try to time it manually.

The exposure is a combination of Aperture (small (high f number) to get the depth of field), flash to subject distance and flash power, it's actually easier to get this in Manual Mode and using a cheap manual flashgun.

The flash duration of a flashgun on low power (used close to the subject) is very fast, in the order of 1/20, 000th to 1/50, 000th of a second which will freeze most action.

Yes.

It's shot using a flash. The shutter speed is irrelevant in flash photography like this.

No you don't need a tripod, but it would make it easier to set everything up.

It's impossible to tell you the settings in advanced - although a wide aperture has been used for the shot, which is why there's such a shallow depth of field. You will need to work out the correct exposure yourself according to the lighting conditions at the time.