This is Manasa, the Snake goddess from the Bengal region.
The seven-hooded snake canopy, the cobra in her left hand and the pot, next to her pendant right leg, identifies her as Manasa. Before the anthropomorphic form came into practice, Manasa was represented by a pot, in the aniconic form.
Manasa’s right hand is in Varada mudra and is, possibly, holding a fruit.
This deep relief sculpture is lightly framed by a backplate and is topped by what looks like a Kalasa. But for her tiara, other ornaments are not discernible. Manasa is sitting on a multi-level lotus pedestal. At the bottom pedestal there is a human figure, in addition to the pot. The human figure possibly represents the donor.
Manasa is flanked by two figures. They could be Rsi Jarat Kanu, her consort and Aslika Muni, the savior of snakes. In some sculptures Ganesha and Karthikeya flank her. In this case, I could not make positive identification, but inclined towards Ganesha and Karthikeya.
Though snake worship by Hindus has a long history, Manasa is a snake goddess and not a snake itself. On that count, Manasa is a late entrant to Hindu Pantheon. Manasa is worshipped for ‘health prosperity, sons and grandsons and immunity from snake bites’.
Manasa worship was prevalent in the Bengal area from the 10th century onwards. The two armed version of Manasa being the most frequent depiction of her. The sculpture is about 11 cm in height and may date to the 14th century or earlier.
For another example see a fragment of a Manasa pot.
Bengal Sculptures Hindu Iconography upto 1250 AD 1992 Enamul Haque