Thank you for reaching out to the Samsung community! The update is available through FOTA i.e Menu> Settings> Software Update>Manually update software. Also, you can check for the Oreo update notification by using Smart Switch PC suite as well. You need to download the PC Suite from below link: http://www.samsung.com/in/support/smartswitch/
Note: Don’t disconnect your mobile phone from PC at the time of software installation. We would love to hear your feedbacks and suggestions related to Oreo Update to further improve our services.
Be sure to hit ♡ when you find an answer that works for you. For Further assistance, you can get in touch with us via Live Chat option by following- http://livechat.support.samsung.com/Customer_new/IN. You can also connect us via Samsung Members web community by following mentioned url-https://community.samsungmembers.com/en_IN#/
