Police said they were on the lookout for persons who had obtained the fake travel documents.
The gang, which charged Rs 30,000 per 'passport', was nabbed on a tip-off that its members used these fake passports and sometimes fake visas also to send fellow Sri Lankans and others to foreign countries, a police release said.
Of the six arrested, two of them had earlier served prison terms for the same crime.
The six -- identified as Mohammed Abubaker Siddique, Devasagayam, Jayasekar, Rajan, Krishnamurthy and Sivarangan -- were produced before a court which remanded them to judicial custody, the release said.
Action would be taken against beneficiaries of the racket since holding such fake documents was illegal, it said.