The estimated value of the tender is 35 million marka ($19.5 million/17.9 million euro), VAT included, news outlet Ekapija reported.
ERS will select one bidder to sign a three-year framework agreement for the procurement. Interested parties can apply by April 23.
The Serb Republic is one of two autonomous entities forming Bosnia and Herzegovina. The other one is the Federation.
(1 euro = 1.956 marka)