The Left's alliance LDF has raced ahead of the Congress' UDF in Kerala according to the early rounds of counting. In the neighbouring Tamil Nadu, the early leads indicate a close fight with the opposition DMK slightly ahead of J.Jayalalithaa's AIADMK.
Earlier, the exit polls have predicted a victory for the DMK which has allied with the Congress.
Meanwhile, the BJP has surged ahead in Assam according to the early leads. Exit polls have predicted that Mr Sonowal will become the next chief minister of the state.
In West Bengal, the Trinamool Congress of Mamata Banerjee has moved ahead in early counting.