Since you are outside the USA, I need to confirm a few assumptions to assure the RCTIP is correct.
I assume you mean the LT285/50R20 Load Range E tires, and that the stock tires for your vehicle are P285/60R18 114V tires with an RCTIP of 32psi Front and 34psi Rear.
If those assumptions are correct, then the RCTIP (Recommended Cold* Tire Inflation Pressure) for those LT285/50R20 tires on your 2008 LC200 is 54psi Front / 56psi Rear.
*According to Toyota:
Tire Pressure vs. Tire Temperature
Tire temperature is dependent on “cold” tire pressure, driving distance and speed, ambient temperature and road surface temperature. As the temperature of the tire changes, air in the tire expands and contracts, changing the tire’s air pressure. The cold tire pressure for all Toyota models will vary and will need to be adjusted accordingly.
“Cold” tire pressure, as shown on the tire pressure label on our vehicles, is generally considered to be the pressure in a tire that has not been driven in the past 4 hours and has been parked outdoors.
HTH