Y S Jagan Mohan Reddy,who won the Kadapa Lok Sabha bye-election in Andhra Pradesh,today took oath. 39-year-old Reddy,who heads the YSR Congress,took the oath in his mother-tongue Telugu. Reddy,who had won the 2009 elections as a Congress nominee,had resigned as member of the Lok Sabha in November last following differences with the party. He launched the YSR Congress and won the Kadapa seat by a margin of nearly 5.5 lakh votes.