Mr. Simić completed his law studies in Novi Sad in 1973. During his studies, he became a student tutor on the subject of Constitutional Law.

After his studies, he worked as a law clerk in the County Court of Banja Luka and in the Republic Attorney’s Office. He passed the bar exam in 1975 and then he was appointed as a Judge of the Basic Court in Banja Luka. Two years later, he was appointed as the Head of the Department. Upon the end of his eight year-term of office as a judge, he was appointed a Deputy General Manager of the Krajina Construction Company. By 1985, he was practicing law and acted in the capacity of defence counsel for persons accused before the International Criminal Court in The Hague. In 1998 he was elected a delegate of the National Assembly of the Republika Srpska, where he was a Member of the Constitutional Commission, the President of Political System Board, Justice and Administration Board and Justice Monitoring Board. He took part in the work of many scientific gatherings.

He served as a Judge of the Constitutional Court of Bosnia and Herzegovina from June 2007 to March 2010.