Mallikarjun Kharge was on Wednesday elected as the new Congress President after he received 7,897 votes, while his rival Shashi Tharoor managed to secure only 1,072.
Although the counting of votes has ended, official results are yet to be announced.
A total of 416 votes were declared invalid.
Kharge's supporters broke out in dance and burst crackers outside the AICC headquarters here.
He is likely to take charge next week a day after Diwali (October 23).
For the first in over two decades, the Congress will get a non-Gandhi President.
Congress leader Rahul Gandhi on Wednesday said that he will report to the new Congress president who will decide his role in the party.
He told reporters at Adoni during Bharat Jodo Yatra that the Congress president will be the final authority and he will decide how the party is going to move forward.
"He will decide what will be my role and how I am to be deployed," the Congress MP said before the announcement of the result of the AICC presidential election.
He declined to answer queries on the role of the president, saying the new president would comment on it.
"As far as the Congress party is concerned, the president will be the final authority. We will have a new Congress president who will decide how the Congress party moves forward," Rahul said.
"Mr Mallikarjun Kharge and Mr Shashi Tharoor are both people with experience and understanding. Whoever gets elected they do not need advice from me. They have experience and understanding and they will decide what to do," he added.
To another query, Rahul said he would report to the Congress president. "Obviously. In the Congress party the president is the supreme authority and every Congress member reports to that person."
Indo-Asian News Service