Hello there, @Kumar1 ...
That's pretty strange. I assume that you are a Canvas administrator at your school since you have access to that screen. I would assume that with your role, the account-level permission for "Account-level settings - manage" is enabled for you? Part of this permission is, "Terms: Allows user to view and manage terms for the account."
Have you tried clearing your browser history/cache, closing the browser, and then re-starting the browser to see if that helps?
Or, have you tried using a completely different browser (such as Mozilla Firefox or Google Chrome) to see if you can edit those terms? What are the browser and computer requirements for Canvas?
Beyond that, I think I would recommend that you reach out to the folks at the Canvas Help Desk to see if they can assist you further with this issue. How do I contact Canvas Support? - Canvas Community
Please keep us posted on things...thanks! Take care, stay safe, and be well.
