Complex sentence: His mother, Rani Maa, spent most of her time playing cards, and left his upbringing on his nanny, and as a result Karan ended up believing her to be his real mother.
Split into simpler sentences: His mother, Rani Maa, spent most of her time playing cards and left his upbringing to his nanny. As a result, Karan ended up believing her to be his real mother.