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In case of a contract, consideration can be either in the form of a benefit to the promisor or detriment to the promisee or else it can be a reciprocative promise.

In this case, it seems to be a reciprocative promise whereby, the promise to repay on whatever terms is itself a promise.

Sec 25 of Contract Act says that 'Agreement witout consideration, void, unless it is in writing and registered...'

For the above case to be a valid contract, the said transaction should be in writing and must be registered'.

Gift, on the other hand is different ,where donee has to accept only and not give or repay. And the consideration is natural love and affection. In gift there is adequate consideration, however, in above case, there is no consideration, is a different case.