You system should be ready to develop it's first NASM - GCC - java project.  But not without our intervention of course.  To complete this we need to do some administration.  But let's first make a test project.  Open Android Studio and in the menu click File - New project.
Give your application a name ex. TestNasm and check include C++ support. Click Next

The window Target Android Devices I leave unchanged to keep things simple. Click Next

In the next window you have to select an activity, leave it also unchanged (unless you have other options in mind), click Next

In the next window you can choose an Activity name, I leave it also unchanged, click Next

In the last window of the wizard, you can customize the C++ support. I choose C+11 with exception support and Runtime Type Information Support just because it is possible and it seems exotic to me.  I have no particular reason that explains why I select this, so leave it unchecked and use the default toolchain.  What is important to me is that there will be NASM support available in a minute (or more minutes)

Click Finish to get rid of the wizard so that we finally can begin.  After a short while our test project is build, configured and ready to be used.  What rest for us is to choose the right emulator (unless you have an Intel based Tablet) to have some output.
Open in the menu Tools - Android the AVD manager.  There you can add virtual devices and probably you should add virtual devices.  Go ahead, create some devices at least one with x86_64 bit support.  If you can't choose then I suggest to stuck with the two I use, later on you can decide to add other devices perhaps some who looks more like a tablet you have in mind.

Having done this, you can test this baby by clicking on the run button. It's a green arrow on top of the window.  When you haven't changed to much in your eagerness, a emulator as in the image below should come up on your screen.

 

When you're done playing with this new project, you can continue reading further for the Assembly Language support (remember, that's the reason you initially are here :) )