Former CM Mamata Banerjee pays homage to Rabindranath Tagore on his birth anniversary, in Kolkata on Saturday. (PTI) On a day when Suvendu Adhikari took oath as the first ever BJP Chief Minister of West Bengal, Trinamool Congress supremo Mamata Banerjee reached out to all opposition parties, especially the Left, with a call for unity to fight against the BJP. However, CPIM reacted sharply to her call, saying she only was responsible for BJP’s rise in the state. CPIM Central Committee member Sujan Chakraborty said, “She has no credibility of fight against BJP. Earlier, she said, she is eager to form a front with the BJP. During her tenure, RSS strengthened its roots in the state … she is responsible for BJP surge in Bengal.” Mamata was speaking at an event at her residence to celebrate the birth anniversary of Rabindranath Tagore on Saturday. “The reign of terror has been unleashed.…