Career
Rnkovic played as a goalkeeper as a youth player. In his first senior year he started playing as a right back for Åssiden IF, which then played in the Norwegian Second Division. He has since been used as a right winger, then as a midfielder until he started playing as a striker in the final year of his contract with Hønefoss BK. In 2005, he signed for Mjøndalen IF and scored a massive 52 goals (46 league and six cup) in just 25 matches (22 league and three cup).
He was wanted by several clubs, but eventually joined Strømsgodset IF. He was mostly used as a sub in the season that saw them gain promotion to the Norwegian Premier League (Tippeligaen).
He signed for Randaberg Illinois in 2007, and after two years there he joined Mjøndalen IF ahead of their return in the first division. He signed for the Slovak Superliga club, MFK Ružomberok before the transfer deadline, but he was never eligible to play for them as the papers did not get approved by the Slovak Football Federation before the deadline.
Rnkovic then signed for Grays Athletic on 22 September 2009 until 2 January 2010. He scored on his debut the same day against Stevenage Borough in a 1–1 draw, gaining international clearance just hours before kick-official
Rnkovic left Grays having made seven appearances, scoring three goals in the process.