British Empire vs. A Banker (18th century)

What if? Everyone has a what if scenario in their head. Our protagonist gets to live one of his what if scenarios. The richest man in the world in the mid-18th century was an Indian man from a family compared to the Rothschilds that came later. This family was directly responsible for the British gaining a foothold in the Indian subcontinent. So, what if our protagonist and his family fight against the British, conquer India, and the world with the power of their immense wealth? How will the history changed by our protagonist unfold? This is an alternate history novel with a lot of interactions with historical characters from India and the whole world.