I have a Nikon D3200 camera. I've always wondered if I can use a selfie stick with the camera.
You won't be able to use a normal selfie stick, it simply won't be strong enough.
However if you have a small tripod (a monopod with adjustable head will also work) and biceps made of steel, you can do it.
If you do have a tripod, just set it up and frame the shot properly. If you want the outstretched arm selfie look then you can easily fake this.
If you have a wide enough lens, you may not even need a stick. Hold the camera by the barrell of the lens with an outstretched arm, this should be far enough back.
This is a "selfie" taken with a small conventional tripod as mentioned by Harry Harrison. I do not have biceps of steel - it helps not to need to hold the camera in position too long. I was prefocusing manually and using a 2 second timer. Swing camera to where it can be activated. Swing out. Relax. Use of a remote shutter controller (Bluetooth etc) may help.
No technical merit claimed for this image :-).
(No tourists harmed in the taking of this photo).
Malaysia heading toward Singapore. DO watch for bridges and the like.
In some countries (eg India) also watch carefully for poles, signals, ... which are often mounted within lethal distance of train.
Selfie sticks work because phones are light, and you can usually use the headphone port to trigger the shutter (taking of the picture). A typical phone selfie stick probably won't work with a dSLR, without modification or additional gear.
However, the D3200 does have a flip-out screen so you can see what you're doing. It does have a tripod mount hole, so you can attach it to a stick to put the camera at arm's length (a monopod with a ballhead mount might be worth looking into). Your only issue is triggering the shutter. For this you can use the timer, a cable release, or a wireless trigger (either infrared or radio). For focusing, you can use a deep depth of field, face-detection AF mode, or, if your triggering system allows, a half-press.
Using this gear, you can actually put the camera even farther away than arm's length, and not have to have your supporting arm in the shot, if you use a tripod. Photographic self portraits have been around for over a century, long before smartphones or selfie sticks, and it's why a lot of cameras come with tripod mount holes, timers, and cable release ports. :)