In Croatia, Rennich families are Croats by relative majority (from Osijek ), rarely Germans (also from Osijek ), and . In the past century, relatively most of Croatian residents bearing this family name were born in Osijek.
Prevalence
Only a few people with faimily name Rennich live in Croatia today, in three households only. They are located in one Croatian city only, in Osijek (<5).
Outside Croatia
Family name Rennich is present in four countries on two continents. The family name "Rennich " is used by some 200 people in the United States , about 100 in Germany , and some 50 people in Canada.
In the sources analysed in the project Acta Croatica so far, the name is mentioned over five times, the first time 1917 in source List of Dignitaries, Officials and Public Servants of the Kingdom of Croatia-Slavonia.