BCCI have announced retention policies before the mega auction, each team can retain 5 players. But the BCCI have also come with uncapped players rule, which will help CSK to retain Dhoni .
This rule was introduced in the first season of IPL, according to it, if an Indian player retired from cricket 5 years ago, he would be defined as an uncapped player. But since then, no team has used this rule.
The BCCI removed this rule in 2021, but now the BCCI is going to introduce this rule again for the IPL 2024. Mahendra Singh Dhoni retired from cricket in 2019, and now he will be considered as the uncapped Indian Player and CSK can buy him by spending only 4 crore.