Step 1: First of all, you need to download Nox version 22.214.171.124 or 126.96.36.199, you get a download link to this version with your purchase but its free so you can also find it here.
Step 2: After downloading, open the downloaded Nox installer file to launch the setup wizard.
Step 3: Click “Install” to start the installation process and then wait.
Step 4: Next, click on the “Start” option which should start the install (simply follow the installation steps).
Step 5: Give it time for couple of more seconds for the setup to end fully.
Step 6: Open up Google play store within Nox and find Marvel Contest Of Champions. (if you can’t find MCOC in the store you may need to change the device that Nox is emulating)
Step 7: And finally, download and install Marvel Contest Of Champions from Google play store.
Note: An optional technique is to install Marvel Contest Of Champions by downloading a Marvel Contest Of Champions APK and drag and drop the APK on the NoxPlayer window.