I was curious to know that if I flip my picture, which is taken from a rear camera, selfie, DSLR etc. horizontally then would it be the accurate depiction of how people see me in real life?
No. The picture straight out of your camera is what you look like to others. You don't need to reverse it. Think about it - when you take a picture of something else with your camera, you don't need to reverse it to see it how others would. (Otherwise any text in a photo would be backwards!) So it's the same when taking a picture of yourself.
You might be interested, though, in artists who have experimented with facial symmetry:
"Both Sides Of" by Alex John Beck, for example, makes images of peoples left side mirrored to the right and vice-versa.
EDIT As mentioned in the comments, your cell phone may reverse the image during preview if you're using the front-facing camera. But once it takes the picture, it's no longer reversed. This is because it's easier to fix your hair/make-up/tie/etc. because you're probably used to doing those things in a mirror.
In case you're using the front camera, this depends on the software you use to take your pics - it may or may not flip the pic automatically. The rear cam always shoots you "as-is", without flipping (obviously).
If you're worried that the front cam flips the image, just check whether the picture is already normal or flipped by taking a pic of anything first with the rear cam, then with the front cam.