TV-MA is a more severe rating than R. TV-MA is the equivalent of NC-17 in the US. Note that R and MA are used by two different groups. The MPAA (Motion Picture Association of America) uses a rating system that you can review here where R is the second most severe, coming up behind NC-17.
M films are recommended for people aged 15 or older. A person needs to be 15 or older to see an MA 15+ film. The content is strong and unsuitable for people aged under 15. However people under 15 can see an MA 15+ film if accompanied by their parent or an adult guardian.
In order to install apk file to the Android device, basically we need to do the following. 1. On Android device, navigate to 'Apps' > 'Settings' > 'Security', enable 'Unknown Sources', then tap 'OK' to agree to enable this setting. This will allow the installation of third party apps and standalone APKs.