Assuming you are using stock timing specifications, 95 octane is suitable.
Be aware that the 3.0 V6 is susceptible to blown headgaskets, IF they have not been replaced (at some point) by a previous owner with the slipper plate steel design gaskets. I realize you are in SA and acces to this style gasket may be difficult. Best thing to do is make sure the engine does not run 'hot'. That means, make sure the engine cooling system (radiator , thermostat, water pump, hoses) are kept in good working condition. Also maintain the exhaust system so that it does not produce any excess backpressure. Due to the engine head / exhaust crossover pipe design, the numbers 5 and 6 cylinders ( nearest the firewall ) run hotter. That is what causes the headgaskets to fail. EDIT -- the 'new' design gaskets can be obtained from Toyota dealerships ( make sure you ask if they are the slipper plate design, just to be sure ).
There is also a steering linkage rod recall currently underway in the USA for many 1st generation and 2nd generation 4Runners and pickup trucks. The linkage rod replacement is free thru Toyota and should include at minimum a toe-in alignment after installation. The original linkage rods have been known to fail under steering load -- generally in an off-road environment ( such as high steering loads against ruts, rocks and roots, etc.). It does not usually fail under normal , on-road driving. You might try contacting a local Toyota dealer with your Vehicle Identification Number to see if your 4Runner is under this recall, and if they are able to perform it for you.
Mike in AR