Raja said Sangma met him and handed over a letter signed by tribal MPs who is canvassing for a tribal leader to be elected as President.
"He told me that he is meeting leaders of several parties. He sought our support. Left parties are meeting on Wednesday. Let us see," Raja told PTI.
In a coordinated move, Tamil Nadu Chief Minister Jayalalithaa and her Odisha counterpart Navin Patnaik had on May 17 announced their joint support to Sangma.
Jayalalithaa yesterday spoke to BJP leader L K Advani, Samajwadi supremo Mulayam Singh Yadav and other non-Congress leaders including Left parties in support of Sangma.