"I will try my best to resolve the differences between (them) if my service is sought," Ramdev told the media during a two-day visit to Bihar before leaving for Jharkhand.
Ramdev said he believed that Modi and Nitish Kumar should shun their political and ideological differences.
He said both men shared the same zodiac sign and were "natural allies" to work together for a larger cause.
Ramdev, however, quickly added that while India needed Modi, Bihar needed Nitish Kumar for its development.
"Modi will become the prime minister after the next general election in 2014. The Congress-led UPA's defeat is imminent as people across the country love Modi's development and patriotic image."
Nitish Kumar has repeatedly made it clear that he would not accept the Bharatiya Janata Party's leadership of a national coalition if Modi is chosen the prime ministerial candidate.