A senior party leader that they support RJD and party leader and Rajya Sabha MP Ghulam Nabi Azad will be attending the rally.
Rahul Gandhi had earlier indicated that he might be present at the Patna rally as Lalu has been a long-time friend and supporter of the Gandhis.
Their presence at his rally, however, may affect its prospects as Lalu and his son are embroiled in cases of corruption, analysts said.
Lalu is attempting a major show of strength after he was ousted from the Bihar government with the JD-U moving out of the grand alliance and joining back the NDA fold and the government with the BJP. (With PTI Inputs)