Hi Senthil,
You can change the browser tab name by using jquery. Here is a similar question with a walk through on how to do that.
https://forum.mendix.com/link/questions/89291
Hope this helps!
Edit: what do you mean previous value? It should change to the value that is set by the entity. I would make sure that value is set correctly. Here is an example that I did.
https://drive.google.com/file/d/15VZ7MnCH7NH22a8HJ43A57CGSs-xUVja/view?usp=sharing