The trade union activists held placards reading "stop repression" and claimed that the life sentence awarded to 13 workers by a court in Haryana is "unjustified".
"Their imprisonment was due to a planned action by the management," union activist Duminda Nagamuva claimed.
During the protest, the Sri Lankan activists also accused the government of Prime Minister Ranil Wickremesinghe of curbing workers rights in Sri Lanka.
Violence had erupted at Maruti Suzuki India Ltd's Manesar plant in August 2012 over disciplinary action against an employee during which agitated workers had gone on the rampage, torching a part of the factory, setting senior human resource manager Awanish Kumar Dev on fire, and beating up and bludgeoning with rods 100 others.