I am trying to redirect my user from a html page to a jsp page which has been deployed on tomcat/webapps using .war file.
While doing so, I am also sending the session information of the user as an hidden parameter via POST method.
With the help of burpsuite tool(security testing tool) one can easily manipulate the cookie and change the username of the user logged in. How will I be able to block such kind of cookie manipulation?
You cannot control/prevent what the browser/client is sending, so do not consider the data received as fact/true. Your application shouldn't just look at the username and say "oh, it's the admin user, I show the whole admin area".
To prevent tampering the data originated from the server or at least detect changes, you use encryption or digital signatures. With encrypted data, it is not possible to change the data. You don't know how to decrypt the data and encrypt the changed data correctly since you don't have the encryption key to do so. With signed data you can still read the data but the signature makes sure that you can detect, if the data has been changed.
In your case, you can use a JWT instead of just the username. The JWT contains a digital signature which is used to check if the data has been changed. Your "testing team" can change the data but your server can see immediately that it has been changed and reject the received (changed) information.