A reciprocal promise is a type of promise where both parties agree to do something for each other in the future. According to Section 2(f) of the Indian Contract Act, 1872, reciprocal promises are promises that form the consideration or part of the consideration for each other. In other words, the promises made by each party are the basis for the agreement between them.

There are different types of reciprocal promises, including:

• Mutual and independent: These are promises where each partys performance is independent of the others. If one party fails to perform their promise, the other party can still fulfill their promise.

• Conditional: These are promises where one partys performance is conditioned upon the other partys earlier performance. If the first party fails to keep their promise, the second party will not be able to fulfill their obligations under the contract.

• Concurrent: These are promises where both parties are to perform their obligations simultaneously.

The Indian Contract Act, 1872 provides rules regarding the performance of reciprocal promises. For example, Section 51 states that if there is a reciprocal promise, both parties must perform their promises simultaneously. Section 52 states that if there is no specific sequence mentioned in the contract, the order of performance of a reciprocal promise is dictated depending on the nature of the transaction.

In summary, a reciprocal promise is a type of promise where both parties agree to do something for each other in the future, and the promises made by each party are the basis for the agreement between them. There are different types of reciprocal promises, and the Indian Contract Act, 1872 provides rules regarding their performance.