Where any person in the employ of Government has under the rules regulating the conditions of his service a right apart from the provisions of this Act or of the Personal Injuries (Emergency Provisions) Act, 1962 (59 of 1962), to receive any sum, whether as extraordinary pension, gratuity, compassionate payment or damages, from the Government in respect of a personal injury in respect of which compensation is payable under this Act, then, notwithstanding anything contained in this Act or the Personal Injuries (Emergency Provisions) Act, 1962, that person shall have the right to receive the sum admissible under those rules and if the sum so admissible is less than the amount payable as compensation under this Act and the Personal Injuries (Emergency Provisions) Act, 1962, then, he shall have a further right to receive an amount equal to the difference between the sum admissible under those rules and the amount of compensation payable under this Act.