@JainRAKESH good day sir,
Both A2A VPN and Cisco GET VPN are based on IETF standard RFC3547, and they can work interoperable, but there are a few things should pay attention to.
1. For AR router, GM function is not under license control, license is required for the KeySever function.
2. When the device connects to a Cisco device that is used as the KS, you are advised to use the Cisco device version of 2013 or later, for example, Cisco IOS Software, C3900e Software (C3900e-UNIVERSALK9-M), Version 15.2(4)M5, RELEASE SOFTWARE (fc2). If the Cisco device of a version earlier than 2013 is used, the multicast rekey may fail.