Hi sourabharora02, glad to see you on Mozilla Support Forum.

You can check for update by following Steps:-

• Click on Menu icon.
• Click on options.
• In left pane, you will see General Menu, click on it.
• In this menu,you will find Firefox Updates option.
• Click on check for updates( if updates are available for you, it will update your browser ).

Thank You.

The System Details list shows you use a quite outdated Firefox 46 version.

Any particular reason for using such an old Firefox version ?

• https://support.mozilla.org/en-US/kb/update-firefox-latest-version