The Bharatiya Janata Party (BJP) decisively won the West Bengal assembly elections, defeating the All India Trinamool Congress and ending Chief Minister Mamata Banerjee's 15-year rule. The BJP made significant gains across southern districts, including Kolkata, and Suvendu Adhikari defeated Banerjee in her Bhabanipur seat. In Assam, the BJP secured 82 seats, up from 60, and with allies leads in 97 of 126 constituencies, ensuring a third consecutive term.

In Tamil Nadu, Joseph Vijay's Tamilaga Vettri Kazhagam (TVK) emerged as the single largest party, leading or winning 108 of 234 seats, short of the 117-mark majority. The ruling DMK, led by Chief Minister M.K. Stalin, was defeated, with Stalin losing his Kolathur seat by 8,795 votes. The TVK is expected to seek support from smaller parties, including the Congress, to form a government.

Kerala voted out the Left Democratic Front government of Pinarayi Vijayan, returning the Congress-led United Democratic Front to power with leads in 102 of 140 seats. The LDF dropped to 35 seats. The BJP won three seats in Kerala for the first time, including one by state president Rajeev Chandrasekhar. In Puducherry, the NDA retained power, with the All India NR Congress securing 12 seats and the BJP four.

Prime Minister Narendra Modi hailed the BJP's victory in West Bengal as 'historic' and emphasized 'change, not retribution,' calling for an end to political violence. He credited women voters for driving the outcome, stating they had 'punished' the Congress, TMC, and DMK. The BJP said its number of elected state legislators has risen from 773 in 2013 to 1,798, with plans to expand further ahead of the 2029 general elections.

The Election Commission is expected to formally notify results by Wednesday, after which the Governor of each state will invite the leading alliance or party to form the government. In Tamil Nadu, the TVK will have to demonstrate majority support on the floor of the Assembly within the next week.