When we go through Ramayana, we can see all type of family relation ships in it. Whenever we talk about brothers we can not forget Rama and Lakshmana. They were always together. It may be due to the fact that Sumitra got two portions of Kheer from Kausalya and Kaikeyi. She gave birth to two children, Lakshmana and Shatrugna. Lakshmana was always with Rama and Bharatha with Shatrugna. So many instances in Ramayana which reveal the love and affection of Rama towards his little brother.
Another pair is Jatayu and Sambathi. Two eagle brothers, also play an important role in this great epic.
Another one is Sugreeva and Bali.
Another one Ravana and Kumbhakarna.