Section 9A(6)(b) in Tamil Nadu Legislator's Pension Rules, 1977
(b)In the case of twins family pension is payable to such twins in equal shares. In the event of any one of the children ceasing to be ineligible for family pension, his or her share of family pension will become payable to the other such child and when both such children become ineligible for family pension the family pension will become payable to the next eligible child or twins as the case may be.