Vijaysinh Mohite Patil is NCP's Lok Sabha member from Madha constituency and a former deputy CM of Maharashtra.
Ranjitsinh, who was a Rajya Sabha member of the NCP, said he was jumping the ship as he was disappointed with top NCP leadership.
This is seen as another jolt to the Congress-NCP combine, after Sujay Vikhe Patil, the son of Maharashtra Leader of Opposition Radhakrishna Vikhe Patil joined the BJP recently.
There is speculation that Radhakrishna Vikhe Patil tendered his resignation as LOP to Congress president Rahul Gandhi on moral grounds, reported PTI.
Some media reports suggest Ranjitsinh is likely to get a BJP ticket from the Madha constituency in Solapur, currently represented by his father.
Lok Sabha elections in Maharashtra will be held in four phases on April 11, 18, 23 and 29 while counting of votes would happen on May 23.
About Mohite-Patil family
Vijay Singh Mohite Patil, a sugar baron and former state minister, contested from Madha in 2014 elections and won. He was accused of murdering his local political rival, Pawanraje Nimbalkar, and his driver in 2006.
The Mohite-Patil family has dominated the sugar co-operatives in Solapur district for over four decades.
The Mohite-Patils are the de facto first family of Akluj, a town in Solapur district, where they weild enormous influence and are revered by local people for setting up schools, colleges, roads and for assisting the underprivileged.