I think Yash did not know about PP
He thought Indrani chose Advay for Chandni
Advay must have impressed him
Indrani was too ambitious
She wanted all the power to herself
So the Mahant couple had to be killed
Indrani could convince people so easily
She also took the help of the superstitious people
She was a master manipulator from the start
so it was not that hard for her
I wish Yash was not involved in the murder