Raghav goes to meet his mother's daughter-in-law's son's only paternal cousin. What is Raghav's relation to the person?

Raghav is going to meet his mother's daughter in law's (who could be his wife or his brother's wife), only son's (who could be his son or his nephew), only paternal cousin (who could be his nephew or his son)

Hence, Raghav could either be the uncle or father to the person he will meet.

 He will be the father if the daughter-in-law in question is his brother's wife. 
He will be the uncle if the daughter-in-law in question is his wife. 
He can be maternal or paternal uncle depending on the gender of his sibling. 

Therefore, Option E is the correct answer.