Transfer of Property Act, 1882
21. Contingent interest
Where, on a transfer of property, an interest therein is created
in favor of a person to take effect only on the happening of a specified
uncertain event, or if a specified uncertain event shall not happen, such
person thereby acquires a contingent interest in the property. Such interest
becomes a vested interest, in the former case, on the happening of the event,
in the latter, when the happening of the event becomes impossible.
Exception: Where, under a transfer of property, a person
becomes entitled to an interest therein upon attaining a particular age, and
the transferor also gives to him absolutely the income to arise from such
interest before he reaches that age, or directs the income or so much thereof
as may be necessary to be applied for his benefit, such interest is not
contingent.