Vasan, who had quit the Congress in November last year along with his supporters, was unanimously elected as party president at the meeting in which TMC functionaries from across the state participated.
A demand seeking total prohibition of liquor in Tamil Nadu was among the 23 resolutions adopted at the meet.
The party said it would launch agitations if a decision was not taken by the government by May 31.
Another resolution demanded establishment of a Lokayukta to deal with graft.