Do you know the Tanii name for this animal ? I asked a few people in Ziro, but couldn't get a conclusive answer. It's the Yellow-bellied Weasel (Mustela kathiah), a high dwelling mammal species found throughout the Himalayas, usually at an elevation of 1800 m and above, though in winter it may occasionally come down to lower than 1000 m. It is a carnivorous species, capturing mostly mice and rats, but also occasionally eating birds and small mammals. In some areas of Nepal Yellow-bellied weasels are kept as pets to chase and catch rodents inside houses.
The picture below was taken at a market in Ziro. A specimen of Yellow-bellied Weasel, probably caught in a trap, was offered for sale, along with byako (Solanum torvum) and a variety of orange fruit.