"I have decided to withdraw from the contest at the late stage because some BSP leaders did not cooperate. I will support and campaign for Congress candidate Subodh Kant Sahay," Oraon told reporters here.
Oraon came to the lime light following his PILs against former Jharkhand chief minister Madhu Koda and some of his ex-cabinet colleague charging them with corruption in 2009.
Koda and his former ministerial colleagues are out on bail now.
Ranchi goes for polls on April 17.