In his message, the All India NR Congress leader said, "Ram Nath Kovind has emerged victorious by dint of his proficiency and capability and distinct services in different capacities."
AINRC had pledged support to the NDA nominee in the presidential poll held on July 17.
Rangasamy had also announced recently that his party would support NDA nominee and former Union Urban Development Minister M Venkiah Naidu in the August 5 vice-presidential poll.