its all irl days, go into your house to the rent menu and you'll find out the cost of it. I think it's something along the lines of 3-500k per 60 days.
The rent prices differs depensing on properties. FOr barns it is around 1mill for 60 days, houses around 3-500k, and DMT around 12million for 60 days. Barack’s, office, storage wearhouses and cargo hq all also have their own unique prices