What's your opinion on this? Is Bathowism a part of Hinduism?

Hi, I'm from Assam and I belong to the Bodo/Boro tribe. Today is my first time posting on Reddit, and I hope this post reaches all my fellow Northeastern brothers and sisters. My dad's family is Hindu, not religiously, but just for namesake, as most of them do not even visit temples or do anything that associates them with being called a Hindu. (I have never seen them doing any kind of ritual or puja.) On the other hand, my mom's side follows Bathowism, or I may say Hinduism because I am confused as to whether Bathowism and Hinduism are the same or not. FYI: Bathowism is the folk religion of our tribe. But, in my case, I'm neither a Hindu nor a Bathow follower. I believe in Christ, and I hope this doesn't cause any problems. I have still not been baptized yet, but I have already devoted my soul and mind to Jesus Christ. Now, the thing is, my grandfather (my mom's uncle) is from Goalpara, and as I mentioned, my mom's family follows Bathowism. My grandfather stays a bit sick as he has become old. He visits a church every day near his house (because there is a Garo community near their village), so I assume that’s where he goes. I overheard a conversation between my mom and her brother about how my grandfather visits the church every day to find solace and how the other members of his family do not like this. They feel that it is not good to embrace another religion when you already have your own religion. I seriously have no words for this, as I can't understand how going to a church is embracing another religion. What's your opinion on this? Because I have no words.