Open your browser and go to the official website: www.rummymaza.com.
On the homepage, find the "Download" button for Rummy Maza.
Click on the button to download the APK file to your Android device.
Go to your phone's Settings > Security and enable "Install from Unknown Sources".
Open the downloaded APK file and follow the instructions to install the app.
Once installed, open the app and register or log in to start playing!
Note: The Rummy Maza app is currently only available for Android devices. iOS users may not be able to install the app unless otherwise announced on the official site.