Identification of Siva is based on Nandi (Siva’s vahana), Cobra (Siva’s attribute), Linga (Siva’s aniconic form) and Ganesha (Siva and Parvati’s son) featured on the base, our left to right. Siva is accompanied by his wife Parvati.
This two-armed Siva, yes only two-arms, is missing his usual attributes, Trishul, Drum, Fire, Ankusha, Mirga.. Parvati is sitting on Siva’s lap and is holding a fruit (?).
The backplate has plain verticals, topped by a kalasa. The backdrop is a circular halo, with five petals radiating out. The Badhrapeetha is also plain.
In a visual sense, not having any distracting design features or patterns on the Prabhavali and the base guides eyes to the deities and the accompanying figures.
The Nandi, Cobra, Linga and Ganesha on the base suggest adoption of Panchayatana concept prevalent in Vidarbha region, Central India. In Vigrahas from Northern part of India, it is not unusual to see Siva’s family showing only Ganesha and missing out their other son, Karthikeya. Not unlike Soma Skanda sculptures from South India, where Skanda (Karthikeya) is shown and not Ganesha.
The central portion of this Vigraha is badly corroded , whereas the top part and the Peetha are intact. See the closeup and the back view. I have not found a suitable explanation as to how this could have happened.
This Vigraha is possibly from Central India. In the absence of similar two-armed Siva it will be a even bigger guess to narrow down the geographic attribution. This Vigraha is about 13 cm in height and probably dates to the 17th century or earlier, going by the level of corrosion.