Rate for a block

How the rate of block is distributed and to whom . Do we have any Apis for that.

Participation rewards are uniformly distributed to all accounts marked online and offline. For details, see https://algorand.foundation/rewards-faq and https://www.algorand.com/resources/blog/rewards-technical-overview
The later has a detailed explanation of what the rate represents.

See also Reward, Rate ,Fraction and Proposer