MDMK founder Vaiko and four other newly elected Rajya Sabha MPs on Thursday took oath as members of the Upper House.
Vaiko, PMK leader Anbumani Ramadoss and two candidates each from the AIADMK and the DMK were elected unopposed as Rajya Sabha members from Tamil Nadu earlier this month.
When the House met for the day, Chairman M Venkaiah Naidu called for oath or affirmation of the new members.
New AIADMK Rajya Sabha members A Muhammathjohn and N Chandrasekaran and DMK members N Shanmugam and P Wilson as also Vaiko took oath in Tamil.
Ramadoss did not take oath on Thursday.
After taking oath, the new members were warmly greeted by Naidu and other members in the House by thumping of desks.
Family, friends and supporters of the newly elected MPs watched the proceedings from the visitors' gallery.
More From This Section
The new members were elected unopposed on vacancies created by expiry of term of K R Arjunan, R Lakshmanan, V Maitreyan and T Rathinavel (all from AIADMK) and CPI leader D Raja.
DMK leader Kanimozhi, whose term would have also expired along with the five members on July 24, quit her Rajya Sabha post following her election to the Lok Sabha from Thoothukudi in the recent election.
With the election of the six MPs, the AIADMK will have 10 members in the Rajya Sabha, while the DMK will have five. The MDMK and the PMK will have one member each in the Rajya Sabha from Tamil Nadu. The AIADMK also has a member from Puducherry in the Upper House.