1. there are 2 life estates
2. one in favour of the widow and after her, in favour of the son
3. the testator has given the life estate to the son subject to he taking care of the family from the rental income
4. now 2 things can happen
5. the condition put by the testator can be taken to be merely as the desire of the testator, which the son given the life estate may or may not honour
6. the above is the defense which the son can take to deny maintaining the family
7. other thing is that since there is a specific condition subject to which the testator had granted the life interest to the son, which he is not fulfilling, the beneficiaries of that condition, that is the dependent wife can file a suit against the husband [your father] to claim the rental income for her maintenance and of that of the family
8. as regards the security deposit, the ultimate legatee is the son [that is you] to whom the property will come after the demise of the son given the life estate
9. now it may so happen that the father may die before the expiry of the rental agreement in which event the property will go to the grandson of the testator. In such a case the grandson will become liable to refund the deposit when the term ends
10. if there is any apprehension that the father is misusing the deposit money which ultimately the grandson has to refund to the tenant on expiry of the rent agreement, then the grandson can also file a suit against the father restraining him from misusing the deposit money and to deposit it in the Court or to deposit it with some escrow agent