Section 5(b) in The Two-Member Constituencies (Abolition) Act, 1961
(b)the sitting member of any two-member constituency. in the State elected to fill the reserved seat therein shall be deemed to have been elected to the House of the People or as the case may be, of the scheduled tribes is from that one of the corresponding new constituencies in which the seat has been reserved, and the other sitting member of that two-member constituency shall be deemed to have been elected from the other of the corresponding new constituencies; and
