Correct Answer: Raja Ram Mohan Roy

Solution : The correct answer is Raja Ram Mohan Roy.

The founder of Kolkata's first "Atmiya Sabha" (philosophical discussion circle) held in 1815 was Raja Ram Mohan Roy. He was a prominent social reformer, religious thinker and the founder of the Brahmo Sabha, which later evolved into the Brahmo Samaj. The Atmiya Sabha provided a platform for intellectual, and philosophical discussions and played a role in fostering social and religious reforms in 19th-century Bengal.