@Puneetjain 

I really hope that it's already resolved by now. They seem to be using Mac binding, your profile when you logon to myExcitel website would have your old router's Mac address listed. So you need to get your Mac address reset from Excitel's end, while plugged into the new router. Their myExcitel app does have that option under profile, but it's crashing upon launch with no resolution for months now.

So either raise a ticket with them, or your LCO can do that. Alternatively, you can clone your old router's Mac address to the new one.

I faced the exact issue recently and this fixed it. Hope it helps.

@RSH99 i was also facing the same issue, but i solve this with copy my Mac address from profile section and replaced : with - in address. From my excitel account.