After Sangma's statement, an independent legislator of the Bihar assembly, Dilip Verma, announced his support for the former Lok Sabha speaker.
"I am sure of my victory in view of present situation in the country. People will vote for me for a change," Sangma said.
Sangma arrived here earlier in the day and was received more than half a dozen BJP ministers and hundreds of party workers.
The BJP's ally and coalition partner, the Janata Dal-United (JD-U), is supporting the United Progressive Alliance presidential candidate Pranab Mukherjee.
The Rashtriya Janata Dal and Lok Janshakti Party are also backing Mukherjee. The presidential election is due July 19.