Yes, the protocol is fully permissionless so no restrictions are in place. However it is not at all advisable to create pools with assets that have a low total supply. Pools should not be created with assets that represent collectables, NFTs or similar.
The system is designed with the expectation that the minimum input and output amount of a swap is 1000 microunits. Swapping smaller amounts than this may lead to rounding errors that negatively affect users.