The players were angered by the performance of Romanian referee Vlad Iordachescu after the 18-10 defeat in Brussels allowed Romania to qualify for the 2019 World Cup in Japan at Spain's expense.
Scrumhalf Sebastien Rouet was handed the longest ban of 43 weeks for physical and verbal abuse of the match official, the independent judicial committee appointed by Rugby Europe said in a statement http://www.rugbyeurope.eu/decision-rugby-europe-judicial-committee.
Fellow scrumhalf Guillaume Rouet was banned for 36 weeks for the same charges. Flankers Pierre Barthere and Lucas Guillaume, as well as flyhalf Mathieu Belie, all received 14-week bans for using threatening actions and words at a match official.
A misconduct complaint against the Spanish Rugby Union will be heard at a later date, the statement added.
World Rugby said earlier this month that it would convene an independent disputes panel to review the match.
Spain must now beat Portugal to earn a two-legged playoff against Samoa for a place at the World Cup.