How did Raghunatha obtain the mercy of Gauranga?

We can best and most authoritatively learn about the life of Srila Raghunatha dasa Gosvami by reading Sri Caitanya-caritamrta. In the Adi-lila it is written: “Srila Raghunatha dasa Gosvami, the forty-sixth branch of the tree, was one of the most dear servants of Lord Caitanya Mahaprabhu. He left all his material possessions to surrender completely unto the Lord and live at His lotus feet.

“When Raghunatha dasa Gosvami approached Sri Caitanya Mahaprabhu at Jagannatha Puri, the lord entrusted him to the care of Svarupa Damodara, His secretary. Thus they both engaged in the confidential service of the Lord. He rendered confidential service to the Lord for sixteen years at Jagannatha Puri, and after the disappearance of both the Lord and Svarupa Damodara, he left Jagannatha Puri and went to Vrndavana.

“Srila Raghunatha dasa Gosvami intended to go to Vrndavana to see the lotus feet of Rupa and Sanatana and then give up his life by jumping from Govardhana Hill. Thus Srila Raghunatha dasa Gosvami came to Vrndavana, visited Srila Rupa Gosvami and Sanatana Gosvami and offered them his obeisances. These two brothers, however, did not allow him to die. They accepted him as their third brother and kept him in their company.

“Because Raghunatha dasa Gosvami was an assistant to Svarupa Damodara, he knew much about the external and internal features of the pastimes of Lord Caitanya. Thus the two brothers Rupa and Sanatana always used to hear of this from him. Raghunatha dasa Gosvami gradually gave up all food and drink but a few drops of buttermilk. As a daily duty, he regularly offered one thousand obeisances to the Lord, chanted at least one hundred thousand holy names and offered obeisances to two thousand Vaisnavas. Day and night he rendered service within his mind to Radha-Krsna, and for three hours a day he discoursed about the character of Lord Caitanya Mahaprabhu. Sri Raghunatha dasa Gosvami took three baths daily in the Radha-kunda lake. As soon as he found a Vaisnava residing in Vrndavana, he would embrace him and give him all respect. He engaged himself in devotional service for more than twenty-two and a half hours a day, and for less than two hours he slept, although on some days that also was not possible.”

In a purport to one of these verses, Srila Prabhupada wrote: “Srila Bhaktisiddhanta Sarasvati Thakura writes in his Anubhasya, ‘Srila Raghunatha dasa Gosvami was most probably born in the year 1416 Sakabda (A. D. 1494) in a kayastha family as the son of Govardhana Majumadara, who was the younger brother of the then zamindar, Hiranya Majumdara. The village where he took birth is known as Sri-krsnapura. One the railway line between Calcutta and Burdwan is a station named Trisabagha (now known as Adi-saptagrama), and about one and a half miles away is the village of Sri-krsnapura, where the parental home of Sri Raghunatha dasa Gosvami was situated. A temple of Sri Sri Radha-Govinda is still there. In front of the temple is a large open area but no large hall for devotees to assemble. A rich Calcutta gentleman named Haricarana Ghosa, who resided in the Simla quarter, recently repaired the temple. The entire temple compound is surrounded by walls, and in a small room just to the side of the temple is a small platform on which Raghunatha dasa Gosvami used to worship the Deity. By the side of the temple is the dying river Sarasvati.’

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Something to do with Nitai as mentioned who asked touched his feet on the head of Raghunatha and empowered him to get the mercy of Gauranga in Neelachala. Eventually, Gauranga instructed his secretary Svarup Damodara to train Raghunatha and finally he reached Vrindavana to meet Rupa and sanatana.

I know about Madhav ghosh .... he was our ancestor.

problematic factor. browse at google. this may help!

COULD YOU PLEASE GIVE MORE DETAILS.