A full-size (150cm/4'9" high) sandstone statue of a seated 'Mother Goddess' figure has been found associated with a temple in Andhra Pradesh. The archaeologists estimate that it dates to the 3rd century BC, which would make it the oldest such figurine found in the country/South India (the article is really not clear). However, there is no explanation in the linked article of how they dated it.
As you can see from the photos in the article, which I couldn't copy here, the statue is not in the best condition, but certainly exhibits steatopygy, or prominent hips, thighs and buttocks. Along with prominent or exaggerated breasts, many archaeologists maintain these features indicate an emphasis on fertility, and are related to ideas of the Mother Goddess.
Such figurines are found around the world, with some of the more famous examples including the Venus of Willendorf, a much older (24,000-22,000 BC) statue found in Austria. The Venus of Hohle Fels, found in Germany, is another example. As you can see, in the European tradition these statues are much older, and are often named for the goddess Venus.
The prevalence of the Mother Goddess idea comes from the research of prominent archaeologist Marija Gimbutas, who wrote a deeply influential series of books on the role of women and matriarchy in Neolithic and Bronze Age European cultures. Her work has more recently come under criticism for simplifying the association between these figures and themes of fertility and matriarchy, and for perhaps imposing modern feminist theory on early societies.
That's a whole different story however, and these Venus statues are much older. The Indian statue, which as I mentioned has been dated (tentatively?) to the 3rd century BC, is much younger. It is also associated with a Hindu temple and hence has been found in a religious context, which suggests some religious function. Hence it has the potential to indeed be a female goddess, but whether it is related to fertility or not is yet to be seen. The archaeologists also say that she appears to be holding grain in her lap, which would also suggest fertility, plenty, bounty, harvest or spring/summer.
It is unclear whether this 'Mother Goddess' is a Hindu deity; there is a rich tradition of Hindu goddesses, and certainly there are fertility deities such as Bhumi, but this statue is unusual in its representation- which is why the archaeologists are excited about it! It's certainly a very interesting find, but more research is needed to understand the meaning and context.
Image: Venus of Willendorf. Taken from Wikipedia and hence licensed to freely share.