Samuria, those are moth orchids (genus Phalaenopsis). They do well potted in coarse bark. You should be able to find orchid bark, or orchid potting mix (that looks like it has a lot of bark) at nearly all garden centers. Brand is unimportant; if it is coarse, with no "fines" (fines = stuff that looks suitable for houseplants), it is probably OK. Ingredients that are common, and OK, are bark, coarse charcoal, and perlite (or similar). I would avoid mixes that contain coir (coconut fiber; it contains a certain amount of salt).
The roots on those orchids look very good. Don't worry too much that they are not down inside the bark; they are healthy. So, there is no rush to re-pot.