Connect laptop/pc to jio modem thru LAN, check the IP and gateway, let's say it's 192.168.0.1 gateway on the modem.
Now change your router access IP to 192.168.0.70
Config router DHCP range to 192.168.0.71 to 192.168.0.150 let's say? gateway on the model/router will be 192.168.0.1 DNS will be 192.168.0.1 or 192.168.0.70. Same thing. Put the modem/router to Dynamic IP mode. Now, reboot both modem and modem/router.
It will work. now. PM me or mention me here if you face difficulties. If you do, please do mention the IP's given by Jio modem and IP access of modem/router so that I can be exact.