"There is no assurance (on supporting Christine Lagarde). We are working on a consensus," Mukherjee said after meeting Lagarde who is in India to seek support for her candidature.
"It would be difficult to say at this moment (whether there will be any common candidate from BRICS Countries) because there was divergence of views in respect of South African candidature. So it is not possible to say whether there will be a common candidate or not," he said.
The vacancy arose last month following exit of Dominique Strauss-Kahn who is facing charges in a sexual assault case.
On India supporting Mexican central bank Governor Agustin Carstens, Mukherjee said he is "a competent person. We are also in discussions with them".
India, he said, "wants election of Managing Director of IMF to be on the basis of merit and competence and to be held in a transparent manner and not on any particular nationality. There should be a consensus".
Historically, the post of IMF Managing Director has been held by a European while the World Bank is headed by a US nominee.
Earlier, the BRICS nations--Brazil, Russia, India, China and South Africa-- had issued a joint statement in Washington questioning the methodology of selection of IMF chief on the basis of nationality.
"The convention that the selection of the Managing Director is made, in practice, on the basis of nationality undermines the legitimacy of the fund," Executive Directors representing the BRICS had said in a statement.