Is it permissible for a father to fictitiously sell the inheritance to his children before his death in order to disinherit some heirs?

A fictitious sale has no reality and does not transfer ownership due to the absence of a price. However, if its intent is to document a gift, there is no harm, provided the conditions for a gift are met. Matters of inheritance are extremely serious and complex; they cannot be settled by a mere fatwa. Instead, they must be referred to the Sharia courts.