I will be buying my first dslr camera soon?

Which one of these will be best for a beginner? Nikon D7100 or Nikon D5300?

If you can only see Nikon, you aren't ready for a DSLR.

The best DSLR is the one that feels right when you pick it up - whether it's Pentax, Sony or whoever.

If you're limiting yourself to Nikon, then of those two the D5300 is nearer to a beginner's camera. The D7100 is aimed at intermediate enthusiasts. It would be a good upgrade one day, though.

Go test out the cameras in store. Youll either love one menu system or button layout. You might love Nikon's, you might hate it. Go see if it feels right in your hands.

Finding the right camera for you can be quite confusing, but I think the best way to do it is not to just have a feel of a few completely different ones for me I tired a few Canon models and they all just felt wrong in my hands and I did not like the button layout, then I tried some Nikon models and they felt much better to me.
after about a year of using Nikon I got to try a Pentax model and it seemed better still.

But if you are already set on Nikon then I personally would go with the D7100 a good website to look at is snapsort you enter two cameras and it compares the specs of each side by side and then marks them out of 100.