What is the ruling on obtaining a sum of money from Al-Riyad Bank through Tawarruq by selling air conditioners owned by the bank, or through shares by purchasing them and then selling them in trading?

There is no harm in Tawarruq, especially when there is a need for it. As for authorizing the bank to sell the commodity purchased from it on credit, it is preferable to avoid it. If it is done, its permissibility is conditioned upon taking possession of the commodities first, and then authorizing their sale. As for dealing in stocks, it is permissible if it is possible to avoid the prohibitions found therein.