Dayakar, who is the child of Sukumar, is married to Priya. Baidehi is the daughter of Sukumar. Sukumar is the paternal grandfather of Garima. Baidehi is unmarried. Raghu is the only son of Dayakar. Priya has two children and one of them is married to Nikita. How is Dayakar related to Nikita?

Let's decode the family tree step-by-step:
Sukumar has a child named Dayakar who is married to Priya.

Baidehi is the daughter of Sukumar and is unmarried.

Sukumar is the paternal grandfather of Garima, meaning Garima is the child of Sukumar's son (Dayakar).

Raghu is the only son of Dayakar. This means Dayakar and Priya have two children: Raghu (son) and Garima (daughter).

Priya has two children, and one of them is married to Nikita. Since Raghu is the only son, he must be married to Nikita.

Since Nikita is married to Dayakar's son (Raghu), Dayakar is the father-in-law of Nikita.