"If Nitish Kumar joins the Grand Alliance again, we have no objection to it," Rabri Devi told media here on Monday night.
However, she made it clear that any decision on this will be taken by top leaders of the Rashtriya Janata Dal (RJD).
Rabri Devi's statement came after Raghuvansh Prasad Singh, a former Union Minister, said Janata Dal-United (JD-U) chief Nitish Kumar should join hands with non-BJP parties to fight against the saffron party.
"He (Nitish Kumar) will surely switch sides but no one can predict when will he do that or what will he say. This has happened several times earlier. It's not surprising... All I want is that everyone should come together against the BJP," he said on Monday.
Singh's offer came a day after Nitish Kumar inducted eight JD-U MLAs as Cabinet Ministers, leaving out the Bharatiya Janata Party (BJP), leading to speculation of a rift between the two allies.
The Cabinet expansion on Sunday came two days after the JD-U chief decided that his party won't join Prime Minister Narendra Modi's new government because it was offered just one seat a "symbolic" representation.
The RJD's relation with Nitish Kumar turned bitter after he dumped the RJD-led Grand Alliance in July 2017 and joined hands with the BJP and formed the government.
( With inputs from IANS )