Sangma drove to the CPI(M) headquarters, where he apprised Karat about the situation in Meghalaya.
The meeting lasted about 20 minutes.
Leaders of Meghalaya Progressive Alliance led by Sangma rushed in New Delhi on Thursday and are meeting various party leaders to garner support against the imposition of President's rule terming it unwarranted and unprecedented.
The MPA leaders are also exploring possibilities of moving the Supreme Court to challenge the United Preogressive Alliance governmet's decision.
After meeting Advani, Sangma said the senior Bharatiya Janata Party leader assured his party's support to NCP's agitation against President's Rule in Meghalaya.
"Advaniji said the north-east unit of the BJP would be with us in our agitation against the imposition of President's rule in the state," Sangma said.
The senior NCP leader said he will also meet President Pratibha Patil and other non Congress leaders on the matter.
When asked will he support Advani for PM's post, Sangma said that "Advani is a good PM candidate."
On whether his meeting with the senior BJP leader had anything to do with both the parties coming closer, he said "Nothing can be said about the post-poll scenario."
"Even Sharad Pawar (NCP chief) has opposed imposition of President's Rule in Meghalaya," Sangma added.
