Hi @Deepak K Anand 

I came across an answer you've provided in 2013 about auto-hiding/collapsing the chatter feed on every page using a home page custom component (Classic interface). 

https://success.salesforce.com/answers?id=90630000000hPNxAAM

Since you wrote that post, Salesforce have retired the ability to add html components. Can you still use the method, but on a visualforce page, to achieve the same outcome?

Thanks