Serbia's Law on Foreigners (Art. 40(1)(10) and Art. 54) makes ownership of real property a ground for temporary residence. Property means residential buildings and apartments in which the foreigner lives; commercial premises, land and rental-only flats do not qualify. The permit is issued for up to 3 years and can be extended; you submit a cadastre (real estate folio) extract or other proof of ownership plus the general conditions of Art. 43 (passport, means of subsistence, health insurance, etc.). The law sets no minimum property value.
Employment, including in your own DOO, is a ground for a single residence and work permit (Art. 40, Law on Foreigners).
Applications go to the Serbian Ministry of Interior. We confirm the current document list with partner lawyers for your case.