Can anyone let me know Airtel Ipv6 Default Gateway of Delhi and Noida?

@Chip It'll only work on that host itself, it doesn't do anything for rest of the devices in the network. I don't think you can make sure nobody uses EUI with SLAAC, you'll need to disable SLAAC, and enable DHCPv6 (or enable both) and allocate address to clients yourself.
 
@wheatbread yep thanks, this is mainly for the devices on the network and my devices get a temp IPv6 address by default. Right now RA is set to 'Assisted' mode which means it can cater to both SLAAC (mainly for some older Android devices) + DHCPv6 via PD. I have switched off the DHCPv6 server on the LAN port of the pfSense box. The current setup works without any problems.
 
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