Samsung has an option for the strides in South Korea, the US and the UK with an option to seek beta testing on the latest Android 6.0 Marshmallow updates on Samsung Galaxy Note5. If the test is rendered success, the users will be able to install the beta version of Marshmallow on some of the selected Galaxy S6 smartphones as well.
Samsung has led the test facility with the selection process of the Galaxy S5 users in the US to receive the initial test build for Marshmallow Beta. However, the test also has been extended with around 200 on the AT & T network with Galaxy Note5 to join the test cycle. As per the latest updates on the test process, the selection has been completed if the first 200 users had completed the instructions and the updates should have been readily available. The firmware update for Samsung Galaxy S6 is similar in build and utilizes the latest security improvements in the update. So the stakes are pretty high on the 2 versions, the Note5, and the Note6.
The company has hinted the release of the build on Marshmallow Beta on February 2nd and the size on install is estimated to be around 1356 MB for the stable release of the update. The other aspects of the features and inclusion in the Beta version are available readily on demand. But if you do own Samsung Galaxy Note5 and use the AT & T Network on your Note5, you could confirm your status on the selection of test users through your mail (e-mail as registered with your operator, specifically AT & T Networks) on the details and processes. The notification on your mail is only subjected on being selected in the test process. Even though, the test process with a test build is always an initial hint of an expected final build in the near future. So you do not need to too poked on the whole issue. There is indeed a source for the final build of Marshmallow Beta that is expected to be available for download pretty soon.