I just like to as if its possible to configure to a router 2 protocols like BGP on WAN and EIGRP on LAN side.
Can I also ask for a sample configuration of it to see how its being set or configured on any typical router
Yes you can run 2 routing protocols on the same router and with BGP this is a common configuration. You would configure the protcols as you would normally eg.
router eigrp 1
router bgp 63251
neighbor 18.104.22.168 remote-as 2845
network 192.168.24.0 mask 255.255.255.0
The above would work fine on a single router. The key decision to make is whether to redistribute EIGRP into BGP and redistribute BGP into EIGRP. The above example doesn't do that but there is nothing stopping you redistributing one protocol into another.