Is it possible to install 2 tiers installation for Talend? Talend runtime on one server and TAC on another server?
Yes, that's how it should be.
First, you need to plan multiple environments: DEV, TEST, UAT, PROD
Then, within each environment, you will deploy the services, with "separation of concerns" in mind.
TAC will go on 1 server.
If you plan to use Central Logging, that will go on another server
Each Job Server or Talend Runtime goes on a different Server.
Nexus, Git, Jenkins/CI, CI-Builder, etc. will go onto a CI Server or a few different places.
If you are doing ESB, and hence, you are referring to Talend Runtime, then you will need to also figure out your requirements for ESB Infrastructure Servers, mutual SSL between the Runtime Servers and end clients/applications for Service calls, etc.