I need to give access to specific users in a realm to a client and not to all users and not even to admin users to that particular client, how shall i do it, please guide me to do it
Keycloak is an Identity Provider, means it is handling authentication.
“giving access to clients” is not authentication, it is authorization. This is done usually by the client application itself (must be done there to be secure).
However, there’s a convenience(!!! security is not its first focus!!!) extension from the community: GitHub - sventorben/keycloak-restrict-client-auth: A Keycloak authenticator to restrict authorization on clients