During his time, did the Buddha visit the northeast state of India known today as Assam? If so, did he give any discourses there?
The furthest east that the Buddha traveled was to Kajaṅgalā (noted in AN 10:28). This area is known today as Kankjol, and is located near the border of India and Bangladesh. So there's no record of any visit to Northeast India, but anything is possible!