They said an official announcement on it may be made shortly.
The government has zeroed on Ramaphosa weeks after US President Donald Trump declined India's invitation to be the chief guest at the parade, citing pressing engagements, including his State of The Union (SOTU) address.
The sources indicated that India was not exclusively looking at Trump's presence at the Republic Day celebrations and that various other options were also being explored.
Every year, India invites world leaders to attend its Republic Day celebrations.
In 2015, the then US president Barack Obama had attended it as the chief guest whicthe h was his second visit to India as American president.
This year, leaders from 10 ASEAN countries had attended the Republic Day celebrations.
In 2016, the then French president Francois Hollande was the chief guest of the parade while Japanese Prime Minister Shinzo Abe was the chief guest at the celebrations in 2014.
The heads of state and government who have attended the Republic Day celebrations include Nicolas Sarkozy, Vladimir Putin, Nelson Mandela, John Major, Mohammed Khatami and Jacques Chirac.