Hi Hemant,
ACLs are the only native Consul mechanism to implement something like that -
https://www.consul.io/docs/internals/acl.html. The web UI supports passing an ACL token along with requests so you'd have to distribute tokens to the authorized users.
For the web UI, some folks bind the web interface only to the loopback interface and then run another web server that proxies Consul's interface, implementing the authentication mechanism (LDAP, basic auth, etc.) up in the other web server.
-- James