"I have spoken to a couple of other chief ministers and decided to attend it," she said.
"There are certain ceremonial programmes under the Constitution. We try to attend such programmes when get invitation for swearing-in programmes of the president and the prime minister," Banerjee added.
The development comes after two MLAs from West Bengal, including Trinamool Congress-turned-BJP leader Mukul Roy's son Subhrangshu Roy, along with more than 40 councillors joined the Bharatiya Janata Party here in the presence of BJP leader Kailash Vijayvargiya who said more TMC leaders will join the saffron party soon.
West Bengal: Setback to Mamata Banerjee as 2 TMC MLAs, 50 councillors join BJP
The dramatic development followed the shock reverses suffered by the Trinamool Congress in the Lok Sabha elections in West Bengal where the Bharatiya Janata Party (BJP) won 18 of the 42 seats -- from just two won in 2014.
Subhrangshu Roy, a two-term MLA from Bijpur constituency, was suspended from the Trinamool Congress for making anti-party comments.
Apart from Vijayvargiya, Mukul Roy also welcomed the West Bengal leaders amid cries of "Bharat Mata ki Jai" and "Jai Shri Ram".
He also said that in different phases every month more and more people will join the BJP.
"In the first phase, we got three MLAs and three Municipalities. Slowly the number will go up. Those who feel suffocated in the TMC because of Mamata (Banerjee) want to join the BJP.
"We will select people. Not everyone will be allowed. Only those who are eligible for the BJP will be allowed," Vijayvargiya said.
He also said that he gave his best wishes to TMC Chief Mamata Banerjee that she remains the West Bengal Chief Minister till 2021.
"But if her 'karma' and people work like this, we cannot help."
Vijayvargiya said that inspired by the leadership of Modi, a lot of leaders from Bengal, not just from TMC but other parties as well, were coming to the BJP.