The religion of ancient Assam was quite different. We can discuss this subject into two main categories.
Here the first category is before Aryan’s came to the land and the 2nd category is after Aryan’s came to the land.
So, let’s crack it one by one.
Before Aryan’s came: – Many people think that the religion of ancient Assam was completely dominated by Hinduism but do you what?, This is not true at all.
Actually before Aryan’s came to this land, here many people lived from different human races. They were such as Mongolian, Austro-Asiatic and many others.
These people believed in different religious beliefs.
According to some historians and anthropologist, these Mongolian and Austric ethnic people worshiped different plant-trees, rivers, animals, snakes, and mountains etc.
They did not believe in any particular god at that time.
These people used to think that their birth has come from all these elements of nature.
So this was the religious belief of ancient Assam before Aryan’s entered to this land.
After Aryan’s came: – The scenario of religious belief almost changed after Aryan’s entered from the northern part of India; but how?
Here is how – After Aryan’s invaded India they started to take over the rule of the whole India and of course Assam too.
Here is why after taking the rule they started to expand their own religious belief among the common people of India and Assam and now I have to tell you that their religious belief was Hinduism.
That is why Assam’s ancient residence slowly slowly started to lose their old religious identity. Over time most of them converted into Hinduism.
No need to go far, I want to give you an easy example of Ahom’s, (However they came far behind the Aryan’s).
At very first, when they came to Assam through Patkai hills, they did not believe in Hinduism but after 300 years later they also were converted into Hinduism (In the days of Suhungmung).