He has been admitted in the Intensive Care Unit of St. Isabel Hospital, Mylapore, reports said.
Reports said he was stable. He is suffering from both allergic bronchitis and high fever.
He was admitted earlier on Friday last owing to dehydration induced exhaustion.
After the phenomenal success of Robot (Endhiran), which was dubbed in Hindi as well, the southern actor has started working on his new film Rana with Deepika Padukone in Chennai.
He plays three roles in the film on the Mahurat sets of which he fell sick on April 29 and had to be hospitalized first.