Hey @aniketdatir,
It seems that the format of your configuration file is not correct, I guess that this is a problem when pasting to the forum. When pasting configuration, please try to use the </> button to enclose the code.
Do you have the module: system configuration in the metricbeat.yml file? Modules configuraton should be in the modules.d/*.yml files. Do you have a system.yml file there?