They have been interrogated for their actual motive behind the security breach, the sources added.
The chargesheet, spread over 1,000 pages, was filed before the Patiala House Court in June and the court took its cognisance last month. A supplementary was filed in July.
The Delhi Police probing the Parliament security beach case for more than 40 days on Tuesday said the six accused were 'self-funded and self-motivated' to do 'something big' for fame.
Four persons arrested in connection with the security breach in Parliament have been charged under the anti-terror law UAPA besides sections of the Indian Penal Code, police sources said on Thursday as security agencies were on the hunt to nab the alleged mastermind.