The strong response from Jio's financial investors means there's not enough for others. Reliance plans to sell about a 10 percent stake in Reliance Retail to financial investors and almost all the $5.7 billion (roughly Rs. 41,985 crores) worth of shares have been taken up, the people said.

The largest allocation is reserved for Amazon, Bloomberg News reported last week. Ambani is offering to sell a roughly $20 billion (roughly Rs. 1,47,384 crores) stake in the retail business to the US tech giant, which could be equivalent to as much as a 40 percent holding. A deal, if successful, would be the biggest ever in India as well as for Amazon, according to data compiled by Bloomberg.

Potential investors including Carlyle and SoftBank could still get their hands on Reliance Retail shares should others cut their commitments, the people said. Negotiations are ongoing and could still be delayed or fall apart, the people said.