If Neena says, "Anita's father Raman is the only son of my father-in-law Mahipal", then how is Bindu, who is the sister of Anita, related to Mahipal?

Explanation:-

Only son of Neena's father-in-law Mahipal---Neena's husband.
So, Raman is Neena's husband and Anita and Bindu are his daughters.
Thus, Bindu is the grand daughter of Mahipal.