Mr Ghosh had been suffering from pancreatitis, his family said. (Special coverage)
Mr Ghosh's residence has been crowded with friends, colleagues and politicians all morning, including West Bengal chief minister Mamata Banerjee. Ms Banerjee said "Bengal has lost a golden director." She also said that Mr Ghosh's body would be taken to Nandan, the state-run movie theatre in Kolkata, for mourners to pay their last respects.
Rituparno Ghosh won 12 National Awards as well as several international honours. His acclaimed body of work includes films like Unishe April (1995), Dahan (1997), Bariwali (1999) and Abohoman (2010). He directed actors like Amitabh Bachchan in The Last Lear, Aishwarya Rai Bachchan in Chokher Bali and Raincoat, Aparna Sen in Unishe April, Rakhee and Sharmila Tagore in Shubho Mahurat and Konkona Sen Sharma in Titli.
Mr Ghosh also directed, wrote and starred in the semi-autobiographical Chitrangada, the story of a choreographer struggling with gender and identity, which won a special jury award at this year's National Film Awards.
Rituparno Ghosh was also a successful TV anchor and acted in the films Arekti Premer Golpo and Memories In March.
Two days before he died, Mr Ghosh tweeted, in his typically poetic manner, about his 20th film Satyanewshi: Wrapped up the shoot of Satyanewshi, a crime thriller in the molten glow of the pensive falling afternoon.
Trinamool MP Derek O'Brien described Mr Ghosh's death as a "loss for advertising, Indian and international cinema."
Actress Kirron Kher, who was directed by Mr Ghosh in Bariwali, called him "a complex character." She described him as "very lonely at one level and friends with everyone at another level."
Director Shyam Benegal told NDTV Mr Ghosh's death was a "huge tragedy."
Noted Kannada filmmaker Girish Kasaravalli said, "He never compromised in quality. We have lost a great character in the Indian film context."
On Twitter, there has been a wide outpouring of grief and shock for Rituparno Ghosh.
Shekhar Kapur: Shocked by passing of Rituparno Ghosh. He was dreaming of getting into what he called his 'next phase'. Hugely creative explorer on film
Anupam Kher: Rituparno Ghosh had great sense of humour. He had a brilliant understanding of human behaviour. Will miss him and his cinema. RIP my Friend.
Arjun Rampal: Absolutely numbed by the saddest news of Rituparno Ghosh not being with us anymore. Loss of a dear friend, adventurous filmmaker. Who taught me so much. A bit too premature departure, will always feel your void my friend. RIP.