Career
Tankulić began his career with Ahlener SG and was later scouted by city rival LR Ahlen. After three years with the club he signed with Borussia Dortmund in summer 2005. After two years with Borussia he signed with Rot-Weiss Ahlen, where he played his debut match in the DFB Cup on 22 September 2009 leading to a contract with the club, signed on 6 October 2009, which runs through 30 June 2012.
On 13 July 2014, Tankulić appeared as a trialist for Dundee in their pre-season fixture against Manchester City doing enough to impress manager Paul Hartley who expressed a desire to offer the player a contract Tankulić and his compatriot Thomas Konrad subsequently signed two year contracts with Dundee in July 2014.
On 28 August 2015, Tankulić left Dundee, with his contract being terminated by mutual consent. In February 2016, Tankulic signed for Regionalliga West club Sportfreunde Lotte.