94th percentile is very good. Congratulations on such a good score. You have done very well considering the difficult situation. I know good kids who have studied for 4 years and have not scored more than 88 percentile.
I moved out of India in 98.I can tell you many stories based on my experience where people have come up from far more difficult situations. I can tell you that we moved back from Amsterdam for very similar reasons. I can tell you about the struggles my son is going through and went through.
But none of them is relevant.
Based on what you have said, your dad seems to be fairly smart.
You may never know what happened between your parents and grandparents. Why he came back when his mother does not treat him well?
I am sure your dad struggles with the consequences of his decisions. He struggles to see his friends kids go to Harvard / MIT and you are going to an NIT. I am jealous when my friend’s children join MIT / Columbia / Princeton…
We all make decisions, and there are some very unfortunate consequences that we know will happen. But we have to take the decisions.
But do not go down this path because I have seen how much heartbreak there is.
My dad was a brilliant mathematician/physicist. He started a program in an university that is now an IIT. We had some challenges in the 80’s and my dad started to believe in astrology. He did all the poojas and vratas … but he could never find peace. It literally destroyed us.
My dads friend went through something even more heartbreaking, but every time I met him I found peace. He would be happy with the Maggi I made for him when I would go to his “bachelor pad”. He taught me how to understand poetry…
The important thing for you is to learn. Not to focus only on the marks, understand what you learn well, so that you can apply them.
No one can guarantee you success. But you have done very well so far. Far more than many kids could have done.
Be humble and continue to be inquisitive.
Focus on exercising, the benefits will last you a life time. Join a Gym. See this video: https://youtu.be/099hgtRoUZw.
Sincerely hope this helps.