I tried to do mongodump and mongo restore from two separate ubuntu instance however, the users, messages, channels are not added in the new instance, can anyone help me please.
Are you upgrading Rocket.Chat versions while doing it? You are using a very outdated version. Upgrading your Rocket.Chat workspace is must, considering the vulnerabilities that were found on older versions.
Check out this script that I just saw from one of our users. It might give you a better understanding about the process: