Those released are Franco Rocchetta, a former MP and founder of the Veneto League separatist party, Lucio Chiavegato, a leader of the anti-government Forconi (pitchfork) movement, Roberto Bernardelli, Riccardo Lovato, Corrado Manessi and Giancarlo Orini, Corriere reported on Friday.
Meanwhile, four others - Tiziano Lanza, Corrado Turco, Stefano Ferrari and Michele Cattaneo – have been placed under house arrest.
"It's good news from Brescia, but it's still shameful that they had to spend any time in jail just for their ideas," Matteo Salvini, the head of the regionalist Northern League, which has supported the movement, was quoted by the news agency Ansa as saying.
The men were among 24 arrested on April 2nd for allegedly plotting to take over St Mark’s Square in Venice armed with guns and a rudimentary ‘tank’ made from a digger.
They were arrested on charges of "terrorism conspiracy and subversion of the democratic order."
The alleged plan came after more than two million residents of Venice and its surrounding region in March voted overwhelmingly in favour of breaking away from the rest of the country and forming their own state.
The online poll, although not legally binding and open to manipulation, showed the strenth of separatist feeling in Italy's northern regions.
The call for independence has sparked similar movements in other regions in Italy.