I configured,
interface GigabitEthernet0/0
description WAN
nameif outside
security-level 0
ip address 203.92.x,x 255.255.255.248
interface GigabitEthernet0/3
description TATA_WAN
nameif Backup-link
security-level 0
ip address 203.192.x.x 255.255.255.248
route outside 0.0.0.0 0.0.0.0 203.92.x.x 1 track 10
route Backup-link 0.0.0.0 0.0.0.0 203.192.x.x 2
track 10 ip sla 10 reachability
sla monitor 10
type echo protocol ipIcmpEcho 4.2.2.2 interface outside
frequency 5
sla monitor schedule 1 life forever start-time now
After I added this config, when I check "show route" it does not display the default route.