"We were thinking that the whole thing would be settled by September, but now it has been delayed due to tax implications," Bajaj said on the sidelines of SIAM annual convention in New Delhi.
"We are supposed to give Shishir Rs 180 crore (Rs 1.8 billion) over and above the transfer of shares at a pre-determined price agreed upon," he said.
Rahul is also supposed to give Rs 47 crore (Rs 470 million) to Shishir's charitable trust.
Shishir reportedly holds 5.7 per cent stake in Bajaj Auto, while Rahul has 55 per cent stake in Shishir-managed company Bajaj Hindustan.