There are various types of companies and models that exist in the property management space. As the market is far older and more mature in the western countries, let's first discuss the models that exist there:
1. Multi-unit buildings - There are large property management companies that manage the rental units in large apartment buildings. They have an office in the premises, and all rentals for any apartment in that Complex are managed by them. They operate by taking a percentage of the rent (usually 10-15%), and also run the maintenance department in the building. They are responsible for rent collection from the tenant, and pay the rent to the respective owners.
2. Single Family homes - In addition to managing large buildings, property management companies also manage single unit homes. Usually some companies will specialize in this space. The business model is the same, and they operate by taking a percentage of the rent when the property is occupied. More often that not, they also charge a fee for placing a new tenant, every time there is a tenant change.
3. Vacant house & land monitoring - In this case, the mandate of the company is to monitor the house or the land, and report status back to the owner. Instead of a percentage of rent, these companies charge a fixed monthly or annual fee.
4. Serviced apartment management - several property management companies specialize in running units as service apartments. They take furnished apartments from property owners, market the properties, take care of all operations, and share the revenue with the owner, with a majority going to the property manager.
5. Guaranteed Rental - In this case, the property management company will lease out a property from the owner, and pay rent irrespective of whether the property is occupied or not. This model usually works for smaller units in a very hot location that are easy to rent.
6. Brokerage firms who manage a few homes as a side business - these are mostly mom and pop shops, who also manage a few homes for their clients. However, it's not something they specialize in or focus on, or only a small percentage of their income comes from Property Management.
7. Facility Management - This is yet another kind of model where the company manages the common facilities and amenities in a large apartment unit, such as the maintenance department, the pool, the gym, the cleaning staff, etc. They usually get a fixed monthly fee for managing the services. They do not manage the units within the apartment complex.
8. Commercial property management - This is very similar to the service apartment model, where property managers will convert the property into a retail unit or a plug and play office by furnishing it, and share revenues with the owner.
In India, Property Management is still in it's nascent stage. It's more focused on absentee owners who don't live in the same city as the property. While several of the models above do exist in India, it is still a young market and the companies in this space are innovating constantly to fill in the gaps that exist. There are many different types of property management companies available in the market. One must research well about these companies, clearly define the requirements and then make an informed decision.