Thanks for being with Samsung and for sharing your concern. We would like to inform you that the device model number SM-J710FN supports VOLTE network. We would like to suggest you kindly follow the below mention steps to overcome the Issue;
Check by using any other SIM card. - Ensure that network frequency of your device should be selected on Auto-mode. - Menu > Settings > Connections > More Networks > Mobile Networks > Network Mode > Select auto mode (GSM/WCDMA/LTE). - Search for the Network manually as follows: Menu > Settings > Connections > More Networks > Mobile Networks > Network Operators > Select Manual Search. - Kindly go to settings >> General management >> Reset >> Reset network settings. - Kindly check for software update.
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#/