It is obvious there is a strong light source illuminating the subject, possibly a flash shining through a medium sized modifier above and to the right of the camera.
A moderately wide aperture was used, probably somewhere around f/4 or so. If f/2.8 or wider had been used, the background would have been much blurrier. And I would guess the shutter speed was also significantly shorter than 1/15 or there would be a lot of motion blur apparent on the dance floor. Without knowing the level of the ambient lighting in the room and the type and amount of noise reduction applied it is difficult to hazard a guess as to ISO used, but in such environments ISOs ranging from 3200 to 6400 are not uncommon to get reasonably fast shutter times, say 1/60 to 1/100 seconds at f/4 or so.
It appears the white balance has been adjusted based on the blown highlights in the white shirts in the background. Fully saturated areas will look white regardless of the WB used, so they are not the best spots to select for using the WB clicker or similar tools. Doing so can get some strange effects at times. If you use the midtones on the shirts, you get a white balance something such as this:
Notice the change in WB also increases the apparent contrast. This is because the colors of ambient light most predominate in the scene are being reduced in intensity while the colors opposite them on the color wheel are being increased. This makes the background look darker.
If you adjust white balance based on the foreground subject (specifically, assume the brightest spot of his most illuminated tooth is white), you get a white balance more like this:
Notice the skin tones in the areas that show the most light from the light source above and to the right of the camera look most natural. Skin illuminated more by the club's pink/blue led lights show the typical purplish pink cast of that type of lighting.
