In a late night release Tuesday, Jayalalithaa said the party has nominated Thangamuthu as the candidate for the Rajya Sabha polls in place of Saravanaperumal.
The party also relieved Saravanaperumal as secretary of the party's student wing.
While no official reason was given for the change, it has been learnt that the party decided to dump Saravanaperumal as cases of smuggling had been registered against him in 1989.
The revised candidates list for the June 27 Rajya Sabha polls is: V Maitreyan, K R Arjunan, T Rathinavel, R Lakshmanan and Thangamuthu.
The six members who will retire on July 24 are: A. Elavarasan and V. Maitreyan from the AIADMK, Tiruchi N. Siva and Kanimozhi from the DMK, B.S. Gnanadesikan of the Congress and D. Raja of the Communist Party of India (CPI).
While the AIADMK has a strength of 151 (including the speaker) in the 235-member house, the DMDK has 29 legislators, the DMK 23, Communist Party of India-Marxist 10, CPI 8, Congress 5, PMK 3, MMK and PT 2 each, Forward Bloc 1 and nominated member 1.
A candidate needs 34 votes to get elected and the AIADMK is expecting to romp home with five seats with the help of other friendly parties and take its tally in the Rajya Sabha to eight from the current five.
According to the Election Commission of India the last date for nominations is June 17. The last date for withdrawals is June 20. The counting of votes will begin at 5 p.m. on June 27 and the election process will end June 29.