"We would be unable to speculate on updates released, as updates are created by Google and released to manufacturers to ensure compatibility.To check for updates on your device, you can go to settings about device and tap software update. Be sure to hit ♡ when you find an answer that works for you. "
Note series never got a beta for system updates, and no reason why they would do that with Note8. Also they never released a beta for phones in India, even for the S series phones, so you wouldn't get it anyway.
Here is a list of security patch logs : https://source.android.com/security/bulletin/
Open them and read in detail about what it fixes. These monthly security patches are Google's marketing strategy to promote their Pixel phones' quick updates. Be assured that Samsung will definitely push a quick update to fix things if at all a serious security issue pops up.
You don't have to worry about security patches unless you have stored nuclear launch codes on your phone, which itself is a bad idea to do so on a non-encrypted phone connected to public networks. Go relax, and enjoy using your phone :)
