MDMK leader Vaiko and 184 others, arrested for trying to show black flags to External Affairs Minister Pranab Mukherjee in Tuticorin last week, were granted bail by a court on Monday.
Judicial Magistrate I M N Kumar ordered their release on furnishing a personal surety of Rs 5,000 each.
Vaiko and members of the Sri Lankan Tamils Protection Movement, mostly MDMK volunteers, were protesting India's "indifference" to the plight of Tamils in the island nation.
A section of the protestors had also burnt a portrait of Mukherjee during his visit to inaugurate a power project on February 28.
All the arrested, including two MDMK MLAs -- Gnanadas and Varadharajan -- were remanded to judicial custody and lodged in the Palayamkottai Central Jail the same day.