They raised slogans like 'Bharat Mata ki Jai' and 'we will strengthen India's democracy.'
Hitting out at the opposition parties for their anti-CAA stand, BJP National secretary H Raja said "a perfect Act has been introduced by Home Minister Amit Shah."
"The Congress and DMK are desperate and are trying to gain mileage by misleading people, Muslim brothers and students on CAA. It is wrong," he said.
Raja appealed to students who have been staging protests in Tamil Nadu against the new law not to get diverted "by such propaganda by evil forces."
It was because of these reasons and to 'protect' Tamil Nadu, BJP was holding such awareness meetings across 12 Corporation limits on Friday, he said.
More such meetings will be held in other cities as well to ensure that their "evil designs" do not fructify, he said.
Former Union Minister Pon Radhakrishnan said "the intended beneficiaries (of the Act) were yearning for such a legislation for 70 years and are now happy."
In an apparent reference to the Congress, he claimed though it supported the idea earlier, that party was now opposed to it.
The BJP had on Thursday shared a video of Congress veteran and former Prime Minister Manmohan Singh in 2003 batting for citizenship for minorities from Bangladesh, uploading a video of his Rajya Sabha speech on its Twitter handle.
BJP leader C P Radhakrishnan, leading a similar demonstration in Coimbatore, said Muslims in India would not be affected by the CAA.
"(DMK Chief) M K Stalin and others opposing the CAA in Tamil Nadu and wanting those from Bangladesh to be protected is laughable, he said.
"This law is to make sure anyone who enters India comes legally and to prevent infiltration...Prime Minister Narendra Modi and the BJP are keen on not hurting anyone," he said.