Indira Ekadashi Vrat Katha, story is associated with King Indrasena. Indira Ekadashi falls in Pitru Paksha (Mahalaya Paksha).
The story of Indira Ekadashi goes like…
Indira Ekadashi is the eleventh day of Ashwin month which falls during Pitru paksha. The legend or Vrat katha of this Ekadasi is mentioned in the Brahmavaivarta Purana as a conversation between Lord Krishna and Yudhistira.
In the Satya-Yuga there lived a King named Indrasena who ruled Mahishmatipura. He was very generous and caring hence he was very rich in gold, grains, sons and grandsons. He was a great devotee of Lord Vishnu and always chanting Vishnu nama. One day, Sage Narada visited him and told about his visit to Lord Yama Raj, the God of death.
In Yamaloka, Narada found the father of Indrasena who was not attained moksha. The father of Indrasena asked Narada to tell his son to perform Indira Ekadashi vrat by which he can get his sins vanished and attain moksha to reach Swarga loka.
Indrasena happily observed Indira Ekadasi vrata and made his father to reach the feet of Lord Vishnu.