Pointing to a girl in the photograph, Rahul said, "Her Mother's brother is the only son of my mother' s father"
How is the Girl's mother related to Rahul?
Girl's mother is rahul's aunt ie: massi.
Mother or Aunt (massi)
If Rahul's Mother's Dad has only two childern, then Girl's mother is his Mom.
If Rahul's Mother's Dad has more than two childern, then Girl's mother can be his aunt also.
Pointing towards Kirti, Manish said, "She is the wife of the grandson of my mother".
How is Manish related to Kirti?