You need to redo your home DB (distribution box) wiring from one phase to three phase
This includes add in rcd,mcb,busbars and a new box, the new three phase cables from the kwh meter to the board, testing and commissioning. Then liasing for the kwh meter installation

Get a second or third party quotation to make the best decision

may i know why u wanna convert to 3 phase?
if u dont mind, can share what electrical appliance in your house.

For five one HP aircon running at the same time, the possibilities of all inductive loads being on simultaneously very high due to the auto temp sensors of the aircon.
The standard running amps roughly 4.5Amps and starting amps 6x minimum thus adding other auxiliary loads will overload the standard 63amps rated protection devices and cabling connection.

For such a situation it is recommended to split the loads to 50%of the rated protection device and cabling connection. Thus adding a three phase incomer supply for safety and peace of mind.For minimizing risk hazard of an electrical fire

Thefor are situations where a very high quality material and installation where the 63Amp rated fuse and oversized cabling will not blow fuse but such situations are discounted from the average situation.

Conclusion for single phase to three phase per standard TNB supply 63amp HRC fuse c/w 16mm2 PVC cable is correct recommended.

Edit* residential internal wiring is only 40/63Amps with 16mm2 PVC copper conductors. O/H hard drawn aluminium conductors to be sized one level higher.