Vanda Orchids grow from a single stem.
Propagation will require cutting the tip of the plant that has aerial roots.
You should be able to see the aerial root emerging from the branch, generally between sets of leaves.
With a sharp and clean knife cut the tip of the plant just below where the roots emerge.
This is a transplant ready cutting.
Put this cutting in a new pot with orchid substrate.
Water the cutting and make sure the water drains away.
Over watering and the cutting will die.
After planting you can use a 20-20-20 orchid fertilizer on the cutting.