The protest saw Congress, TMC, SP, AAP, RJD and CPI come together against the government.
CPI(M) was also invited to join the protest held just before the days proceedings in Parliament began at 11 AM.
Gandhi said the protest was being held against the government's attitude of curbing the Opposition's voice.
"The government does not want democratic expression and democratic voice," Congress vice-president Rahul Gandhi said.
"We want our voice to be heard in Parliament, Mann said after the protest.
"It has sent a strong message that opposition is united and when it comes to issue of nation's integrity we will make our voice heard," said Gaurav Gogoi, who has participated in the protest.