Hello @Banerjee, Somdutta , a SignalR client connection requires a connection token which is issued by the SignalR Auth API and signed using an Azure AD access token issued by Azure AD to the security principal backing your App Server and which is the one that calls the Auth API. For more information take a look to Client-side authentication while using Azure AD.
Azure SignalR Service only supports Azure AD authentication for the management plane but not for the data plane means that clients will get authenticated using a SignalR, not Azure AD, issued tokens.
Let us know if this answer was helpful to you or if you need additional assistance. If it was helpful, please remember to accept it and complete the quality survey so that others in the community with similar questions can more easily find a rated solution.