IOS 10 Beta 6 version

You should be aware that any beta software by its nature may be incomplete or unstable. People download it to assess it and report problems to Apple. It's generally inadvisable to download beta software onto a critical device; if you do so you must make sure to have comprehensive backups first in case of problems. You should not regard it as simply as a way of getting an update earlier than its release.

Other than this, we are not allowed to answer questions about beta software in these forums. If you sign up to download it you will have to sign an non-disclosure agreement (meaning you agree not to discuss it with anyone else) and told how you can provide feedback on it to Apple.

You can install if you want, but almost all betas of any app or os will be unstable, and if it stops working, you can always downgrade with iTunes, and an IPSW file. go to ipsw.me to get one that matches the phone and version that you want. then go to iTunes after the file is done downloading. plug in your device and click update while holding option on a mac, and shift on a windows. find the IPSW file you just downloaded, and update with that, let it do its thing, and it will downgrade back to iOS 9.3.4.