Multisite Robots.txt Manager is a free wordpress plugin to manage all Network Websites robots.txt files directly within the Network Admin.
Manage all Network Websites from one Administration area.
Mass update the entire Network or update a unique Website.
Each Website within a Network can have a unique robots.txt file.
Robots.txt file examples that can be published to Websites or stored as a default.
Login to wordpress (wp-admin).
In your admin dashboard click plugins and select Add New.
Type Multisite Robots.txt Manager in the search field and click Search Plugins button.
Install Multisite Robots.txt Manager.
After the successfully Installation click the activate Plugin link to activate the plugin.
Download Multisite Robots.txt Manager wordpress plugin. Download link.
Unzip and upload it to your WordPress wp-content/plugins directory.
Login to wp-admin. In your admin dashboard click plugins and activate the Multisite Robots.txt Manager wordpress plugin