Notaris is equvilant of a lawyer that specialise in land issues. The laws here are different from singapore. they are based on Dutch laws.
If you have a land title under your name, you have KEEP YOUR TITLE PROPERLY. There is no single govenment agency that keep all records. It is all with notaris. And there are many of them all over the country.
If you lost it, you have to make a police report and get it replaced.
There are cases where there are 2 land titles to the same piece of land. Be very sure and check properly before buying. Usually, that arise from family issues, and all the person holding the land or immediate family members have to agree to it too.
The process of buying and getting the final title deed can be very tidious too. Not one way ticket like singapore. You have to go to different departments and get all other documentations and wait and wait.