Career
Rnić signed his first professional contract with Partizan in June 2003, on a five-year deal. In the following three seasons, Rnić made less than 30 competitive appearances for the Brussels-based club, before being loaned to Germinal Beerschot in January 2011. In July 2011, Rnić returned to Partizan by signing a one-year contract.
After more than six months without a club, Rnić signed a contract with Ukrainian club Hoverla Uzhhorod in March 2013.
He moved to Austria in August 2013 by joining Wolfsberger Air Corps.
Rnić represented Serbia and Montenegro at the 2006 Union of European Football Associations Under-21 Championship in Portugal. He also represented Serbia at the 2007 Union of European Football Associations Under-21 Championship in the Netherlands, winning the silver medal.
On 8 June 2005, Rnić made his senior debut for Serbia and Montenegro in a friendly game against Italy at the Rogers Centre in Toronto. He also made two appearances for Serbia in 2008 under the managerial reign of Miroslav Đukić.