Skunks

I have a friend with a Mikrotik RB750 router that on the WAN side is connected to a leading ISP. On the LAN Side, he sambazas the connection to 3 other networks from different institutions.

He asked me to help apportion the main bandwidth accordingly to each of the institutions on a certain ratio. Any one who can guide on the steps of how I should go about it?

Best regards,
Kevin