Answer:
Answer unclear... more context would be helpful.
Step-by-step explanation:
This sentence has a blank that should be filled in with a noun.
Given that the phrase "made up of 50 representatives from each of the five member tribes" is referring to a council, the best noun to fit in this sentence could be "council".
Therefore, a possible answer to the sentence fill-in could be:
"The council was run by a council made up of 50 representatives from each of the five member tribes."