Can I sell the inherited property before registering it in my name?

Not effectively. In practice, a buyer's attorney will insist that the property appears in the Land Registry under the heir's name before the sale is completed, and any mortgage lender financing the buyer will require clean title. You should obtain the succession or probate order first, then register the transfer in the Land Registry, and only then proceed with the sale. Attempting to shortcut this sequence causes significant delays and can cause the transaction to collapse.