Sources said those who have come forward to donate their plasma have recovered from COVID-19 at the Sultanpuri and Narela quarantine centres.
Many more have volunteered to donate their plasma, they added.
The Tablighi Jamaat, a religious organisation in south Delhi's Nizamuddin came under intense attack for the spread of coronavirus after it allegedly organised a congregation after the lockdown and even when the Delhi government had imposed curbs before it.
In the therapy, transfusion of plasma from recovered patients to severally-ill COVID-19 patients is conducted. Convalescent plasma is an experimental procedure for coronavirus patients.
Sources said several Tablighi Jamaat members at different quarantine centres have also volunteered to donate their plasma for the recovery of COVID-19 patients.
The move comes after an appeal was made by Chief Minister Arvind Kejriwal last week to patients, who have successfully recovered from coronavirus, to donate their plasma for treatment of COVID-19 patients.
Kejriwal said the initial results of plasma therapy on critically-ill COVID-19 patients have shown "encouraging" initial results.
Last week, Tablighi Jamaat head Maluana Saad Kandhalvi also appealed to the organisation's followers who have recovered from the infection to donate their plasma.
A Delhi government official said the process of taking plasma from the Tablighi Jamaat members has started.
According to Dr Mohammad Shoaib, who is facilitating the exercise, till now, 10 Tablighi Jamaat members have donated their plasma to help other coronavirus patients.
Shoaib said he is not related to the Tablighi Jamaat, but he is acquainted with its followers. He also claimed that the Delhi government requested him to involve Tablighi Jamaat followers to donate plasma.
The exercise commenced on Sunday evening after the iftar at Sultanpuri and Narela quarantine centres following which a team from the Delhi government's ILBS Hospital and another private hospital visited the premises, he said.
The Tablighi Jamaat congregation which took place in March was attended by nearly 9,000 people, including foreign nationals.
After that hundreds of Tablighi Jamaat followers were quarantined at different centres and many were booked for alleged misbehavior with the staff there.
On April 18, at a daily media briefing about the COVID-19 situation in the country, Lav Agarwal, Joint Secretary in the Ministry of Health, said, "A total of 4,291 COVID-19 cases or 29.8 per cent of the 14,378 coronavirus infections reported till that day were linked to the Tablighi Jamaat congregation."
According to the bulletin released by the Health Department of the Delhi government, on April 10, when the total number of COVID-19 cases were 903 in Delhi, 584 infections were linked to the Tablighi congregation.
Since then the Delhi government dropped usage of the "markaz", the centre of the Tablighi Jamaat after the Delhi Minorities Commission raised an objection over it. SLB BUN PR TDSTDS